Some husbandry questions.... (Mainly to do with temps)

So if/when I get a baby ball python(trying not to get too hopefull) I plan on keeping him in a plastic 15q tub. And I have a few questions. ;)
1) Is a wider and shallower 15q tub better than a deeper and not as wide 15q tub?
2) http://www.reptilebasics.com/ve-100 is this a good thermostat? I'm looking for a proportional one, and if this isn't a proportional one, what is a good(fairly inexpensive) one?
3) What size and brand heat mat is best for that sized tub?
4)Is it easy to get a temperature gradient in a tub so small? If not, the ambient temp should be
85*f right?(If not please correct me!)
I think that's everything I wasn't sure of...

Nevermind on the 'if that thermo was proportional or not. I just saw it was on/off. Couldn't see that at first.
So I guess my question stands at'what is a fairly inexpensive but good quality proportional(sp? Too tired to check ATM..) thermo?

-Go with the wider, shallow tub. I have a 15qt tub that measures 16"L X 13"W X 6 & 5/8"T.

-The Under Tank Heater for a tub that size will need to be small. Either an UltraTherm or ZooMed in the 6" X 11" size, or an Exo-Terra Heatwave Desert in the 8" X 8" size. Or, ordering a piece of Flexwatt heat tape is also an option.

- Here are your choices for a proportional thermostat:

Reptile Basics- VE-200...$114.99
VE-300...$139.99

http://www.reptilebasics.com/thermostats


Helix- DBS 1000... $139.00

http://www.helixcontrols.com/DBS1000.htm

Spyder Robotics- Herpstat...$109.00
Herpstat II...$199.00
Herpstat Pro...$299.00

http://www.spyderrobotics.com/home/products.html

Vypyrz as usual has answered everything perfectly. I'll just pick up your last question.

A true temperature gradient (2" per degree) is not possible in a small tub. There is no exact evidence it is needed either. Providing a hot spot and cooler spot is enough. A gradient requires space and distance tubs in general drop off too fast and are too small.

Again it is not needed few people have a gradient most just have a hot spot and cool spot with little to no distance in between.

Ambient temps of 85 are on the high end of ok 79-85 for ambient air temps. I tend to try for the middle with temps rather than an end. It allows for fluctuations, inaccuracies.

My personal temps are cool side 80ºF hot side 90ºF and the ambient air temps are about 82ºF . The middle of the ranges. Little snakes often do a bit better with cooler temps (faster metabolism) so ranges like 78-80 C 88-90 H and ambients about the same are fine for little snakes as they grow temps can be raised a bit.

After a few months and you soon to have snake settles in and is eating for you. After you start to know it better you can adjust the temps based on the snake. If it is always seeking cool temps you can drop the cool side temps a touch if she starts to regulate some. If always on the heat raise the cool end temps. You can adjust for the individual, always maintain the hot spot just ensure it isn't too hot.

So I'd(of course) put the heat pad on the hot spot, and in a tub that small, it should help heat the rest of the cage up to that much? It only needs to be 78-80 on the cool side, so that should be easy enough to obtain...
And the hot side temp is just controlled by the thermostat.
Those are all good working thermostats I presume? If so, I just looked at and like the Spyder Robotics- Herpstat.
Feel like I'm forgetting something....
But anyway, thanks for the replies!

You have it :) I recommend heat tape also though. Where will the tub go?

More floor space is always better.

There are a few places the tub can go in my room... It just mainly depends on if my rat is still alive when I get the snake. If she isn't, then I have a whole table I can dedicate for the snake, if she is, I'll clear somewhere off. I have a spot by my bearded dragon, but It's by the hot side, and 1, the snake cage could make my bearded dragon cage too humid, 2) the light might disturb the snake 3) the heat lamp might dry out the snake cage.
So I guess not there. XD I normally find room.

Okay as long as it's on a nice surface and not on carpet or material or anything, I would totally go with the flexwatt heat tape. I got mine from big apple pet supply or whatever they are called.

Okay... Flexwatt heat tape... how much of it would I need and where would I put it?(*isanooobwhenitcomestoheatape*)

Flexwatt is fine or just a UTH or heat cable it really doen't matter much. Personally I'd not bother with flexwatt for a small tub. You would need a small bit (6" of 3" wide) and then to wire it and such it just isn't worth it for a small single tub. You will be upgrading the set up in 6 or 8 months so I world go uth the small ones and use it for warming rats... :D it is only 12 $ so not really a problem just grow the pad until you hit the larger tubs.

I like herpstats myself. The others are also have good reputations too I have used a helix and herpstats. Rich is great to deal with (VE200) so no issues there either basically similar units and features, it doesn't really matter much pick one.