What engine are you talking about exactly? the D15B7 out of the DX? If so, building the B7 isn't as easy as building a Z6 but it can be done. The Z6 has more options cuz it's a 1.6L and there are just more parts in general for it cuz it's usually the only SOHC that has a chance of staying in the car from the factory. If you have the cash, i would personally swap out the old engine for the Z6. It has more displacement, better flow and VTEC. Rods and pistons are readily available, especially low compression 8.5:1 pistons. Look at the HondaTuning's Budget Boost Part 2 on their web site for more great info on boosting this engine for minimal cash.
A second option: Build a Mini-Me engine!
Pick up a Z6 head, a P28 ecu, and rods and pistons. Rods and pistons are available for the 1.5L but i've noticed that not as many companies make them, you'll have to search around. But again you have a 1.5L vs. a 1.6L. If you did this engine right, you would probably save yourself $300 easy though. B)
Mini-Me's are P.I.M.P too...the really poor man's LS/VTEC. I like the inovation of them...very lah-de-dah
Personally i would rather a z6 as well, but down at the local drag strip (qualcomm stadium, race legal 1/8th mile) I met a kid with a jdm d15 vtec built up a bit running 10 psi on a t25 and he's one of the fastest hondas out there. i believe his best was 7.6 @ i dont remember mph. keep in mind this is 8th mile, and thats only 10 psi.