A lot of owners use fleece or VetBed . It wicks the wee throw, you need something absorbant underneath. Don't use sawdust or woodshavings, not good for their breathng or feet and coats. Equine bedding (unscented) like Auboise or Megazorb are good and dust free.
Guinea-pigs are not tidy animals BTW. The hay smells more than they do and it gets everywhere!
Mine have cardboard, puppy pads, newspaper and hay.
In winter I put a thick later of those small animal safe wooden cat litter pellets under the puppy pads (roll up the puppy pads newspaper and hay and throw out). My guineas don't chew puppy pads but they do like cardboard at 3am 
Indoors they have cardboard (especially important to have a good thick protective layer to protect their feet from the C&C floor grids) , a couple of batmats under their sleeping areas then as above (puppy pads/newspaper/hay)
I;ve used fleece but I don't want to risk my washing machine. You can brush the hay and hair off with a rubber brush then put in an old pillowcase to wash (tie with a hairband or string). I found the coarse thin fleece wicked better than plush fleece. Ikea and Primark are worth a look . Old towels too.
I give them looroll tube shreddings when I've got enough.
All the guineas I've had have liked sleeping on hay , our boar pulls the hay from his petbed onto the floor to sleep on (but he's an odd little animal).
If you're getting piglets you might find the C&C grids too big (they're 1" square approx) you can line the insides (I use cardboard boxes to come up the sides ) or overlap , but you'd need more grids.
Lardy adults - no problem.
We'll need pigtures when they arrive.