The top mounts are available, either from ebspares or main dealers, they are about £75/side though!
If you intend to just chuck the old bits away intact, then you will also need the little cup at the top that the nut sits in (no idea what this actually does though!) the bump stop/dust cover, theres also a rubber pad the top of the spring sits in and a metal spacer that goes between the bumpstop and the top mount!
If you dont have a impact driver then getting the old nut off is a challenge!
When I replaced mine, one top mount was fine, bar a little corrosion, the other was really grindy and graunchy. Might have lasted years, might have failed in 6 months..
How are your front wishbones? these are easy to replace with the struts out, and are a weak point.