I assume by swap you mean motor swap, easy B18C1 aka a GS-R motor. You can pick them up used with 30-40K miles on them for around $3,000. Dont put a B-16 in your car because everyone and their mom will laugh at you as it cant make the same power the bigger motors do. Dont put an H22 in as there is little aftermarket support for it. The B18C series and K series make the real juice. If you can afford it go for one of those (K series has the most potential). If you are on a budget the take your LS motor and make it a power happy LS/VTEC. good luck