Very good idea to use the entertainment center for a viv! I bet it will look great.
I couldn't really tell you offhand if plywood is any good, but you can always get melamine from home depot.
I would suggest either a reptisun 10.0 or a aracadia 11% for a
uvb bulb. You should figure out how want to place the uvb, which light fixture to get, and how you should place your decorations so she gets the optimal uvb. you can figure out the optimal uvb using this site.
https://sites.google.com/site/thelizardmadness/lighting-guides
For basking light, it really depends upon where you live and the temperature. You could just grab a 150 watt bulb from home depot or some place like it as well. I would also suggest getting a dimmer so that you can adjust the temperature to your liking (this is also sold at home depot and the like).
I won't vouch for things I haven't personally used or seen someone reliable here use for items. My dimmer, basking light, basking fixture, and dimmer I got from menards and got them pretty cheap and they are reliable.
For a light timer, I use this.
http://www.amazon.com/gp/product/B018G86I08/ref=s9_simh_gw_g60_i1_r?ie=UTF8&fpl=fresh&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-1&pf_rd_r=0K2NWFP3F0M56Y04TJWS&pf_rd_t=36701&pf_rd_p=2079475242&pf_rd_i=desktop
Make sure you set the days to 14-15 hours.
For temp gauge, I myself got a laser temp gauge. Laser temp gauges and probe temp gauges are the suggested temperature gauges to use. Make sure it can also detect humidity if you get the probe temp gauge, that way you get two birds with one stone.
For substrate, you should get something like textured tile, newspaper, paper towels, and some versions of repticarpet. I suggested textured tile if you can get it done right as its easy to clean, files down the nails, and looks good. Some people suggest sand or other loose substrate, but I suggest against pretty much all of those due to risk of impaction, disease, and you have to constantly purchase more to replace it. Can't even just wash it.
Obviously you need stuff such as branches, hides, and things to climb on and in, but most of that is subjective of where you want to get it. Just check on anything you get, especially stuff from the wild. For outside branches, you need to make sure its the right type of branch (pines are bad for beardies, pretty sure there were some others) and that you clean it off thoroughly. If you want to do that, there are steps you can follow online to properly clean a branch.
Feel free to ask some more questions! Always happy to help.