There's so much to learn about these great animals that we keep, that I think it's a great idea to share ideas and practices with other keepers. Even simple questions have numerous personal choices that apply. 
Frozen food: I purchase my rodents from RodentPro, who packages their rodents in bulk, and then vacuum seal 'feeding portions' per my feeding practices. I've never had any problem with adult prey items really sticking together (thanks to their fur) but I have found that pinkies are prone to it. Since the four animals you have are all bigger than what would require pinkies (even as newborns), you shouldn't have any problems. On the odd times that adult animals are somewhat frozen together, I've still had no problem just pulling them apart because the fur basically keeps them from sticking together but so much. Also, feeding frozen prey is more cost effective and convenient, at least in my opinion. As for defrosting, I simply place mine in a sink full of hot water (from the tap). Because of how many animals I have, I usually have to change the water a couple of times before they're all thawed.
Caging: I use a mix of cages myself - mostly Vision plastic cages, a few tanks, a few Sterlite tubs and soon to be a few homemade melamine cages. The plastic cages/tubs and melamine are much easier to heat than glass aquaria IMO, but the good old aquariums do in a pinch and are ideal for certain types/species of animals. I use either heat tape on a thermostat or a heat lamp with all my enclosures. I've not had any problem with my plastic Visions melting around the heat lamps with the exception of one - because I used too high of a wattage bulb by accident. Luckily cage and snake are both fine as it was caught relatively quickly. You can also use radiant heat panels to heat the plastic cages with no ill effects.
Liners/Substrate: I've not used any of the liners that are now on the market, though I've heard they're nice. I dare say blank rolls of newsprint paper would work just as well though. For all new arrivals, I use newspaper (cheap and easy to clean) while I pre-treat for mites - I don't take any chances and treat the snakes whether I see mites or not. In the past I've used aspen shavings (great for small collections but real time consuming for large collections). Aspen is very absorbant and looks nice though it can be messy and gets pulled out every time you take the snake out of the enclosure...at least it did with my guys. I now use old cotton sheets...attractive, very absorbant, cost effective (easily picked up in yard sales or Goodwill for just a couple of dollars a set) and are reusable. The pillow cases work great for small tubs/cages and can double as a holding bag for snakes while you clean cages. Solid wastes are shaken into the trash or commode and the sheets dumped into the washer with bleach and detergent. I like to keep two sets for every cage, so that if I have to clean all the cages at once, I have enough sheets to replace the soiled ones. It takes me a fraction of the time to clean cages now than it once did when I used aspen, plus I like the look, and the snakes seem to like crawling through the layers of the folded sheets. I can't take credit for the idea though, that came from a guy named Henry who used to frequent these forums a couple of years ago.
Hope this answers your questions.
Raven
