dude listen, first of all dont stay SOHC, that should be just a given now use your common sense. with three grand you could have a mildy built gsr or ls turbo, as other ppl, said. ls turbo is a good option for u i would say. but where im from theres a guy around here selling a 1998 acura integra gsr sedan for 1500$ and all it needs is a new clutch, front end and rear end is mint and it comes with swirlies.
so, think about it, if you could find sumthing like that you could buy the car, sell the front bumper, rear bumper, 98-00 tails, and swirlies right off the back no problem and easily make back lik $800. not to mention everything else u could part out (cluster seats dash etc etc) and your left over with a GSR motor, that u basically spent $500 for. and now you habe $2500 to build it.
plus once you part the s**t out of the car you can still take it to the junkyard and theyll give you $200!!
so dude, think about it, i would say go LS-turbo, Ls-Vtec if u get a good price on a nice b-vtec head, but better than anything id say buy a cheap GSR sedan lik i said, or find a wrecked gsr with a good motor.
whatever you do DONT stay SOHC, you're just driven down a dead end road doing that. I kno ill probably get flamed from the SOHC people on here but IDC the single cam motors are good reliable DD and THATS IT.