My face when I tell my brother about going vert:
[URL="http://img809.imageshack.us/img809/6205/aliensguy.jpg"]View Image[/URL]
That shit had me cracking up .
Sounds like you've got most of your questions answered, but i'll toss my in also.
1. Vert racks are not a good choice for a beginner grower. They require a lot of advanced knowledge/grow technique to properly utilize/dial. That said donuts are the bout the easiest way to grow known to man.
2. The little muffin fan doesn't have to be one of the Honeywell's everyone loves so much on here. I've successfully cooled bulbs with box fans, honeywells, and even larger metal ones like you are using now. For cooling a single bulb the Honeywell is definitely best, but they all work fine. However with multiple bulb stacks (3 or more) it seems to work better with a stronger fan (i.e that big metal version you are using). With a big metal Honeywell style fan blowing straight up and 14" exhaust right over the bulbs (two 600's and two 400's stacked) I can comfortably hold my hand within a 1/2" of my bulbs.
If you'd like some more vert rack ideas, or just good information in general, read through my redemption thread. Started as a vert donut, but pretty quickly evolved into the vertical rack monster it is today .