Whats up.

Yes both fans on one adapter will work fine. Ive used 7 fans on one adapter before.

Ive been using the hell out of a PC box i made. I use it to germ seeds and veg for a little while before they go into my tent.

Its come in handy but ill tell you i have had to rework the shit out of it. Biggest issue is heat. make sure your fans are sucking hot air out. Also the lights should be mounted across the top not pointed down to give more vertical space for growth and heat buffer. I actually mounted a fan hanging under the bulbs to make sure they dont burn.

Also you might want to add two more lights. I use three 6400 and one 2700k. It makes the plants bushy as hell. Sorry about all the extra info I just dont want you to go through the pains i did.

Also I hope you have a dwarf strain because its way too hard to take a regular strain full cycle in a pc case... even with LSTing. Not impossible though.

Another good tip is to cover your passive air intake area with some panty hose, or if your fans are powerful enough, some dryer sheets. This prevents all the nasty stuff that is on your floor from getting sucked in and getting to the plants.

Dont forget to get some cheap flat white spray paint or myler for the inside and not tin foil. All the reflectiveness you can get is important when using CFLs.