Heating question

Im currently using heating pads with a thermastat but was wondering what brand of UTH and themastats most people use thats the cheapest but more importantly dependable. I plan on getting the vision cages V332 and will need more heaters as im getting more cages and snakes.thanks

Also what size heating pad do you use for tanks that measure 30" x 12" and 36" x20".

I use ZooMed Heating Pads, works great for me and controlled with a light dimmer. Never had problems.