Hey guys, I have had my Ar for awhile now and am finally trying to find a pair of irons to put on it. I've got myself an ATI omni .223/5.56 with a magpul MOE mid-length handguard so I am going to need a gas block front iron sight, anyone have any advice on a good sight that isn't to expensive to bust my wallet? My budget right now is about $50-$80 but I don't really wanna hit any higher than that. You would be my hero if you have a good pair of front and rear irons that are in my price range but otherwise please leave your comments down below on what your opinion is.

Magpul polymer sights would fit your price range however polymer may warp from the heat from the gas block so something metal would be more appropriate.  You could do a metal front sight and polymer rear to save money but may look funny. I'd look at yhm sights. Or magpul mbus pro. The pro version is metal. This is a really good price for the set.
mbus pro sale

Second the idea of metal front sight. Gets really hot really fast. But don't forget if you get metal flip up front sight to let that shit cool down before flipping them down.

I run a Yankee Hill Machine Gas Block Mounted Flip Front Sight (http://yhm.net/gas-block-mounted-front-flip-sight.html) on my Stag M3. New they are a little outside your price range yes, but I got mine on Equipment Exchange for around $50.  In the rear I use a Magpul gen2 MBUS and it has worked great for me so far.  The front sight even folds down perfectly on top of my MOE handguard if you mount the sight backwards to fold towards the receiver. Just my 2 cents.

The important question here is, is the rail on the gas block the same height as the rail on the upper? If so, sight combinations will be easy to match up. If the rail on the gas block is lower than the rail on the upper, you have to make a different choice for the front sight. Midwest Industries makes a front sight that is designed for that very situation as well as standard front sights.

MI sights

I have the gas block that is lower than the receiver. I have a Yankee Hills Gas Block Riser (from Primary Arms) under a Magpul BUIS Pro.  I would not recommend this setup.  I will likely switch to a Troy or Diamondhead  front side designed to sit on the low gas block.

The Magpul Pro sight does not sit perfectly on the riser,. but hangs off the front.



http://s1237.photobucket.com/user/mountainman2011/media/Bob%20Stuff/RiserandBUISPro.jpg.html