i would use as tall a PC tower as you can find...
look up on craigslist till you find one that you like... new ones can be sort of expensive, if you get an old computer, you just have to gut it out, and keep the power supply for the fans.... you will need two fans, one pulling air in, and one pushing out... the one pushing out should be at the top, the intake at the bottom....
if the computer you buy has only one fan, get the second one from newegg.com, case fans, they have really cheap ones for like 2 dollars... just wire it in parallel with the intake fan (look this up if you don't understand)......
for the bulb you should get a single 68 w CFL, or if you can fit, 2 42 watters... one daylight in color, another one softwhite..... to wire them you could use clamp lights, and just run the wires out the back of the pc case... if you wanna be real stealthy about it, you can try and fit a small multi-plug inside it, the type that can make 3 extension chords into one.... not the ones that have the little switch and everything.... that way you have a single wire running out the back.....
for smell build yourself a small carbon filter, or use ona gel...
good luck
for reflectivity spray-paint the interior of the box with white spray paint.....
i'd go for one plant, topped off at the 4th node... and LST,a screen, and anything else to keep the plant small, cuz it's gonna want to outgrow that box.... for a growing medium i'd use soil... but that's up to you....