I have a SOHC VTEC, and I've owned a DOHC VTEC. There is a difference. And they're not apples to apples stock. There's no doubt that if you drop turbo or SC into it, or I/H/E into the SOHC and not into the DOHC, that it's gonna go faster. But as SiR-DC2 said above.... you can do so much with a grand or $1500. It's not necessary to go jump off and do a B series swap. The D series are good engines too... don't think that if you don't have a B16A or a diff DOHC that you're engine's sh!t and that you might as well just start over again.
-Mindi