Congratulations of your forthcoming piglets 
Have you decided where they are going to live? They need a fairly constant temperature, away from draughts and damp.
Have a look at C&C cages (there's a website on Cavy Cages). You can customise them and add as you need to. You might want different levels which you can do. You might want to do a sleeping area, a food area and a 'corridor'.
I have a small animal pen for mine at night. It's got seperate panels that connect. At the moment it's a 5'x3' with an extra bit going to the window bay. (They have the small bedroom for nighttime). I was a bit worried in case our little boy tried to escape but so far he's too lazy. (He can stand up on his hind legs in the travel box but that's solid)
I have a 4'x2' cage - the deep plastic base with the bars top bit that can lift off. Fine for small pigs but ours are now 3 yo and about 6 months.
They definately need the space, one of the biggest issue with boars is territory. They like to be able to get away from each other if they want to.
They'll need hay, a few hiding spaces, water bottles , spaces for food bowls.
Bedding choices depends what you and your pigs like.
Megazorb or Carefresh is good to absorb smells and wee.
VetBed or fleece is washable and lasts ages, but you need to wash in a pillowcase or your washing machine gets all clogged.
I have tried all sorts, my boys liked deep hay best.
Bedding I use is : outdoors, cardboard, newspaper, soft barley straw (because mine are adults) and hay.
Indoors - a tarpaulin on the floor (it's on carpet), cardboard, paper puppy pads and towels (cover up the pads in case they chew). Then a trug of hay and shredded paper.
Our older boy is getting a bit 'middled aged' now. I put lovely fresh thick cardboard down in the bedroom cage and he was all
"I can't walk on that ".
So a load of towels had to be laid out, like a cloak over a puddle, before he lowered himself to walk. 
Good job we all love him - spoiled pigs.
Baby guineas like alfafa hay but it shouldn't be given to adults. I got some when I first got our piglet. Pets @ Home does alfafa cubes which look good.
Good Luck 