All the stuff you linked looks good. To regulate the UTH, you'll need either a rheostat (lamp dimmer) or a thermostat. I recommend using a dimmer as a backup to any thermostat. Look up the Lutron 300W at lowes.com. The cheapest (but hey, it works) thermostat is the Reptitemp 500R, which can be found at reptilesupply.com.
To black out the sides and back, I use black foam board from walmart. I glued a terrarium background to the inside of each panel to give the tank a jungle look. You can atach the boards to the tank using blue tack so it can be removed easily.

On a side note, if you've been using that UTH unregulated you could be burning your snake as they get way too hot. I would turn it off immediately until you get a thermostat or a rheostat.

As I won't be on the forum until tomorrow afternoon, if you need any help feel free to ask any other member, or do a search in the forums for keywords.