If you go dohc, you need the harness, and computer. You'll also need the MAF. If you really want a cool project, turbo the 3 cylinder. It'll be cheaper, faster, easier, and way more odball than a stock dohc. There's an excellent tech support group in TS, and I can walk you through any problems.
The 98-01 1.3 16V is pretty widely available. It's lighter than the dohc, multiport injection, and capable of similar power. We have one with very minor tweaks that easily hangs with my sons 02 RSX.
This was a real budget turbo 3 build by one of my customer on a stock Metro motor with only sensor trickery for extra fuel.
http://www.youtube.com/watch?v=QJJRhIF3KXE&feature=related
There's another one with better sound, but not as good a run.
AngryCorvair wrote: and that right there is why 90% of the time i think ZW is a berkeleying douchebag.