First, I think you're making a great decision by going with a tub instead of a glass tank. I, like a lot of others here, started with a tank and quickly changed to a tub and won't be looking back...

So, about your setup, here are just a couple things I would recommend...

-No need for a heat lamp above the tub. The lid is solid rather than being a mesh screen, so it's not going to do much good at all. The UTH should provide sufficient heat for the whole enclosure. Thermostat is a must. I have the 500R and haven't had any problems with it, but I know others have.
-I personally do not have foil lining the tub to disperse heat. I don't know if it's really necessary. I just forgot to put foil on mine before I stuck on the UTH.
-As for ventilation, I personally put holes in the front, back and sides of the tub, but none on top. I keep the top of my tub covered with a black blanket to block light and make my bp feel more secure.
-I do still offer identical hides, however some will say this is not necessary in a tub/rack setup.
-I also found that paper towels work best as substrate in my tub. I tried both cypress and aspen and both caused the humidity to jump way too high. With paper towels, I maintain 50-55% humidity, which can be adjusted during shed by adding a damp paper towel on top of one hide or by changing to a larger water dish.
-Digital thermometer/hygrometer is a must. The stick-on dials can be very inaccurate. They do sell combos. Most members here recommend an Accurite from Walmart or Lowes. I find it works best to put the probe inside the warm side hide, the actual unit on the cool side to measure cool side temp and humidity.

Sorry for the long post, but that's what I've found works best for me. Good luck with your setup, and don't forget to post some pics when you're done!