I own an L96 airsoft rifle, good gun,depending on the brand.
If you have the money for either of these I would suggest them, the original body of the guns would make them easier to mod.
Gun 1
Gun 2
Just on a side-note, airsoft GI is probably one of the best airsoft retailers I have come across. I've only had 1 problem with them, they forgot to include something in an order, but when I called and told them about it, they over-nighted it to me with no extra charge.
Edit: JG guns have gone up in their reliability the past few years, as have the CYMA brands as well(atleast on their AK line).
also, if you're planning on making an AR or a BR I would suggest using a FAMAS as a base (Not sure if anyone mentioned modding one in the thread, thought I saw something). The bullpup design of the FAMAS would make it a fairly simple body mod, no mucking with the internals.
Edit 2: Forgot to answer the "can it work?" question. Yes it would work, you just have to mod it. airsofters have been modding guns since the sport first appeared.