I finally have obtained the funds to get an AR. I have roughly $760 to spend.

I have heard the best from Bushy and Colt. Any advice on what to get with these kinds of funds?

Your probably a tad short ($) for a Colt or Bushy.
You could easily piece together a Rock River Arms Standard A2 for that.
adcofirearms.com is a good place to get the complete upper and complete lower you need.  You would obviously need to have the lower transferred through a local FFL.
Rock Rivers are pretty much equals in quality to Bushmasters and Colts.  There are minor differences that may or may not matter.  Lack of chrome lined barrels and high shelf in the lower to keep you from making a full auto out of it are a couple that come to mind.
____________________________________________________________________________________
You could buy a complete RRA lower $215.56 and a 16" A2 upper $395.00 for a total of $610.56 for new parts. Then just pay someone to transfer ($15-25) and buy a USGI mag for $15-25 and you would have a brand new RRA rifle. If you buy a complete lower and complete upper, it just pushes together and you push the pins and it is ready to go. And comes with RRA lifetime warranty on complete uppers and lowers.____________________________________________________________________________________
if you are interested and need help/advice on how to go about it, or it sounds to easy to be true, feel free to ask/Instant Message/email, etc...