Hi Louise
I had Georgie neutered a little while ago and Anne did a lovely job. Isuflorene is the correct anaesthetic to use, this makes up the bulk of the expense! Cat gut stitches should NOT be used as GPs often have severe allergic reaction to them, so disolvable stitches are best. There are 2 methods I believe but the best is something called the "closed ring" method.
Send in some veg, pellets and hay so the pig can start eating as soon as he comes round. Have in some bio lapis and maybe fibreplex too incase there is a problem with gut stasis which can happen from the stress of the op. Bed on vet bed and change daily. Examine the area a couple of times a day to make sure no abess or infection sets in.
Worthwhile asking your vet how many GP neuters he/she has done!