I think a VE would be a good option, you can get a very low mileage one for about $1200 (SR16VE) and I don't know about emissions but it should be fine.
The SR16VE will still be alot nicer than your DE and wont be that far behind an SR20VE; all you need to convert it to a SR20VE is a new crank and then it will have the SR16VE cams which kick ass in NA setups as it will raise the compression. If you aren't already, sign up at
www.sr20forums.com and search for threads posted by Andreas Miko. He will also be the guy you want to talk to to get the engine.