We have been in our house a year now and are thinking it would be smart to shop around for a new alarm system. The home already haswireless sensors for all the doors and windows so wondering if I would be able to buy a new alarm and reuse the sensors or is it better to just do a full new system? Also what systems are good out there these days. The wireless sensors are all in good shape and have had no problems with them although changing out all the batteries is going to be kinda expensive. Are the systems compatible regarding the wireless sensors? I was thinking it would be cheaper to just do the monitoring service as a stand alone since all the hard work is already done on the install.

Budget wise, we are hoping to keep our cost down so no exotic setup, just basic security. Suggestions?

What part of Texas are you in? I install security systems, fire alarm, access controls and cctv systems in the Houston area

I am in the dallas area so a pretty long haul from Houston. Any thoughts on what systems are good?

As far as systems go, there are really just a couple brands that everybody uses. Brinks , ADI , pay to have their name put on the same system the smaller companies use. Ademco panels are very nice, and used by just about everybody. After them i would suggest First Alert. The FA panel is a very nice one as well. I would stay away from Caddex , and DSC but  thats just my opinion.

If you are looking for an alarm monitoring service, you might look into Smith Thompson. They provide monitoring, including cellular, for only $16.95 a month. They also do not require any long-term contracts. They are locally owned in the Dallas area and have been in business for over 30 years. Quite a deal! I have not used them, but I have been researching this issue, too.

I checked and my current system is a ademco 250P1. It is a pretty full system with wireless on all windows, doors, motion sensors for different zones, sirens, etc. The problem is I looked and really have no clue how it is all wired and am dumping the expensive alarm service. I was thinking I could reuse all the wireless sensors, motion detectors, etc. so I just have to buy a new controller for a DIY so i can go with one of the cheaper monitoring services. I figure it is worth spending a couple hundred to buy a new controller and save the money every month. I can probably save $25/month which would pay for the new stuff in a few months.

So the real questions I have are
1. can I reuse all my existing stuff if I stick to another ademco unit?
2. Is this going to be a project I can do myself hooking up a new controller?

I am trying to keep my cost down and don't mind doing some installing as long as I don't have to run new wires thru the house. I assume since I already have all the wires in the metal box from the alarm company setup. it will be fairly simple. I do have the diagram they provided that tells which wires are what. What do you guys think?

If the panel is working correctly you can reuse it, the sticky part is getting into programing and removing te account number and dialer number. If you have a Alpha keypad ( words are displayed instead of numbers ) you could do it yourself.

Re reprogramming: I can't get any help from the alarm company since I had to give them 30 days notice I was switching. I only have a couple weeks to get something done so need to act pretty quick. I was planning on just ordering one of those do it yourself ademco systems that just comes with just the basic stuff and reuse everything else. Maybe something like this http://www.safemart.com/Honeywell-Ademco-Vista-Alarm-Kits/Ademco-Vista-20P-Wireless-Starter-Kit-V20PWRLS-KT.htm

Do you have a alpha keypad ? If you do than you just have to go into a couple of program fields to delete the info.  With a new system you will have to program everything.

I too have been researching this issue for my parents.  It seems like there are a lot of satisfied Smith Thompson customers, and they can "take over" most existing alarm installations.  Wireless/cell phone monitoring looks to be included for the $16.95 price.  

http://www.smiththompson.com/smiththompson/existingsys.aspx?mode=2

I don't have an alpha keypad. That is why I thought it might be best to get a new system that comes with new controller and keypad.

Getting a alpha key would be cheaper and easier than installing a new system.