i have a couple thoughts on this regarding lights, electrical, strains and construction. I'm still a newb, too, but my gear is working well. Check my grow for case pics, etc.
1st: Construction.. Use a drill w/ metal bit to get the rivets out. Go slow, but firm hand directly in the center of the rivet. It will break and make your job much easier. Also, flat white spray paint works just as well as the car reflctor stuff and is probably cheaper. Make sure there's no gloss at all. Flat only.
2nd: Strains.. Everyone is all about lowryder when talking pc grows. Personally, i think it's a poor choice, but do whatever fits your grow. Any ruderalis (smaller, autoflowering) strain is virtually uncloneable, so you will have to go from seed just about every time. If you live in a place where buying seeds is a tough thing, like i do, you want to be able to clone. Any short indica should be just fine. Hell.. Anyone growing from bagseed in a pc box in the states is likely growing mexican sativa, which gets monstrously tall. You do not *neeeed* lowryder. Just get something which has a rep for staying small. Most of the seed sites have strain info. Including general height. I went w/ citral and top44, but virtually any kush will be fine, too. If you've never had hindu kush, do it!
i think the pc / cfl types on here have settled on 80/20 indica/sativa for pc cases as optimal. It capitalizes on the size of indica and the strength of sativa in a fairly optimal way. Also, i hear lowryder tastes like ass, which has kept me from it.
3rd: Lights. You shouldn't just strap in any old cfl. If you are doing a veg. Only box to replant outdoors or to move into another chamber, like i'm doing, you want to have 5500 or better rated cfl's. They are perfect for vegetative growth, but they are hot, so you will need to beef your fans up. I use 3 high powered ac fans in my veg. Case. If you are building a separate flower case or have an autoflowering strain, you want maybe 2500 rated cfl's, which are perfect for flowering. These are cooler temps and you can go with lesser fans to keep temps down.
4th: Electricity - i think there's a little misinformation regarding wiring up fans on here. 99+% of pc fans run on 5v dc power. If you plug ina 5v dc fan to a 12-15 v dc cell phone adapter, you will be spinning the fan 2-3x faster than it was ever designed to go. Engineers that build things usually design for a particular lifespan, as well, so you will cut your fan's lifespan by up to 66% or will increase your chances of a failure / electrical fire by up to 66%. Do not just plug these into whatever you have lying around. As a homeowner with a family, it just isn't worth the risk. You want lower volts and higher amp rating. Consult your electronics store. Just tell them you're trying to wire up some old computer fans for a science project and they can help you measure out what's right. I just consulted some electrical engineers that i worked with at the time.
also, regarding yield, there's a guy on here, v12xjs, who says he yields about 1g / day in a perpetual grow from seed. That's enough for him and, frankly, that's plenty for me, too. If you like, check my grow for the box (i just sprouted) and definitely see v12xjs' grow if you're curious about the real possibilities with a pc grow. He's posted on my grow, so you can find him there.
Cheers!