hey, everone here has told you what to use.
Can I ask what size the PC case is? And are you Hydro, soil , or other??
Yeah, CFLs in my experiance, which is small are great for indoor, or in your case, stealth growing. From my experiance with 125watt plug and grows and now 250watt plug and grows, the minium you will need is two bulbs, one in the 2700k and one at 6200k. These are the two respective light spectrums a plant needs to grow. However Im growing with one and then the other and have no adverse effects. Using the 6200k as a veg grow light and then the 2700k for the flowering. The 6200k is a blue light and 2700k as a red light.
If your not using femaine seeds blue light tends to produce more females, from my experiance and red more males, so from me using one then the other I have found more females are produced. About a ratio of every 4 plants one has come out male.
So for your grow inside the reflective PC Case , depending on if the buld will fit in. (PLUG AND GROW bulds tend to be about a half inch smaller in lenght.Envirolites are slightly longer in lenght.) This is me talking about the 5 lights I have, only using two in two rooms(boxes) and 3 are plug and grow and others are envirolites.
This is why I ask what size the case is.
Personally I would go for maybe two 250watters one in each spectrum. This way you are covering your bases for amount of light and the power consumption of the 250's compared to th 125's isnt a massive jump up BUT THE LUX is!!!!!!!.
You will find slighty more heat from the 250's, but maybe a degree(c) inside your enclosed PC case.
Hope that helps/.
Take it easy...