As far as the water dish, hop over to oreileys, pick up an oil drain pan for 3 bucks ( they can fit like 6 quarts in the 3 dollar ones) if you don't like it being solid black, pick up some 100% silicone(non toxic and much cheaper than aquarium silicone), cover the outside of the drain pain with silicone and apply gravel/reptile bark and some fake moss. This is what I use on large snakes that like to soak. Just clean it real good and use plain for 3 bucks or make it custom for under 20. As for heat lamps I use a 60 watt red bulb 24/7 alone with no other heating accessories. It keeps loki's 15 gallon at 77 to 79 cool side and 86 to 91 on hott, with variations on cold days, so I up to my 75 watt those times. But it's pretty hard to actually recommend a overhead system without actual experience in your geographic area, enclosure size, substrate Amount, etc. It's really just trial and error, constantly monitoring temps and humidity til you find what works. Only to be doing the shuffle all over again come winter time lol.
What a great idea for a water bowl. Well done on that one.