Getting a bite free 1911 can be done very economically but don't confuse "economy" with "cheap". You get out what you put in so it is best to start with a good base. Personally, I use a series 80 Colt and have no issues with carrying a series 80 BUT the Series 70 style guns ( sans later model firing pin safeties ) are your best bet in terms of ease of maintanence. This leaves you with either Colt or Springfield as a choice. The major difference you want to consider here is the internals. As far as the frames and slides on Colt Ser. 70 and Springfield 1911s they are both excellent. I have found that INTERNALLY Colt uses better parts by and large. In each case, however, there are some parts you may want to replace. I'll leave that for later.
GETTING A BITE FREE 1911 ON THE "CHEAP".
After years of dickering around with 1911s I've found that extended beavertails and such are completely unnecessary unless you "need" a high hand hold. I don't. There are easier and much more economical ways of getting a bite free 1911 than having to grind the frame and go through the process of fitting an extended beavertail.
First, the Hammer.
On the Colt and Springfield guns, the spur hammers are perfectly suited to defensive needs if you simply remove four notches from the lenth of the spur and then reprofile the hammer. In fact, I find them personally superior to rowel ( ring ) hammers. thrity minutes of work ( less if you have access to a mill ) and a trip to a bead blasting cabinet and you have a very acceptable hammer.
Next, the rear of the frame and the grip safety.
This is the the section of the gun that probably causes more comfort issues than "spur hammer" bite. Both Colt and Springfield tend to have rather sharpish frame tangs and grip safeties. Simply putting a light radius on the rear sections of the frame, just lightly, you don't have to go crazy, adds tons of comfort. Again, you don't have to ruin the lines of the gun, just soften them up at the portions of the frame where the web of your firing hand wraps around the gun.
With the grip safety, you can round off the rear, lower sections of the safety where it glides over the web of your hand. Use a bit more radiusing here because during recoil the grip safety does make contact with your hand fairly firmly.
ETA: I am adding as I go along here....bear with me.....
Another section of the gun it helps to soften is the edges of the trigger where the pad of your finger engages the surface of the trigger. A simple radius on the edges of the trigger works wonders for comfort. If the trigger has a "serated" face, stone those edges down just a bit, too. It's an amazing difference.
On to reliability. 1911s were designed in the days of much cheaper labor and better management. These days, you have three managers for every ten employees and most of them are strung out doing several jobs to the man. Management, meanwhile, is off running amuck as usual. In the case of the 1911 this has led to a more inferior gun than was turned out in the days of yore. Still, the workers are trying the best they can and you can do a lot in short order to cover what they were forced to miss on occasion.
One of the big offenders that causes reliability issues with a 1911 is the tuning and design of the extractor. I have noticed that both Colt and Springfield use an extractor with a claw height of .149 inches. The old school claw is around .170 inches high and takes a nice big grip on the case. Wilson Bulletproff and Cylinder and Slide make nice beefy extractors.
I highly reccommend you study the fitting and tuning of a good extractor and add a Wilson or C and S to your firearm. You will not regret it.
The safety. Most folks these days use the big ol' gas pedal safeties made by nearly everyone and their dog. Personally, I stick with the old school one. If you go with an extended safety....feel free to trim down the fat to just what you need. It's less obtrusive and doesn't look so silly. Use Wilson if you go this route. Again, I think it is unneccesary.
Slide stop. It stops the slide. Does it work? Then don't sweat it. If you must go with an aftermarket slide stop go with a Wilson Bulletproof. It's an excellent design, very smooth and unobtrusive with a very classy look. NOTE: there is a trick to some slide stops to get them to function properly and at the right time. Study this, it isn't hard but it is an area you should know.
DAH DAH DAHHHHHH!!!! The PLUNGER TUBE. A simple, component that need serious looking to. I cannot believe how many loose plunger tubes are running around out there...especially on NIB guns. When you start working on your gun, have it PROPERLY restaked as a precaution. A buddy of mine and I thin up Permatex "Permalock" with acetone and put a few drops on a degreased frame at the plungertube junction to the frame before we restake it. Rock solid.
Springs: Wolff heavy duty springs. Find out what the best weight is for Commanders and go from there. The key is the recoil spring and firing pin retrurn spring. A heavy duty plunder tube spring unit from Ed Brown is also a good idea.
Sights: A dovetailed front is the best way to go but a properly staked unit is fine. Use what you like. Make sure whoever does it...knows how to do it RIGHT. Me, I just used a Robar Heavy Duty GI rear sight. Conventional look, nice and tough.
Now, I have more to add, but I have some other stuff to do right now...so here is a picture of my carry 1911. Note, this gun is more tuning than anything but it does have an aftermarket extractor ( C nd S ) and some otehr do dads I'll get into later. There is not more than 250 dollars into the gun. I carry it constantly and VERY comfortably. Ignore the HiPower.....IF YOU CAN!!!!