In reply to kathrync:
Good quality 8-speed will be hard to find off the shelf.
As I see it, you have two choices, buy cheap ones from Decathlon and replace as and when required or get something build up especially.
If you were to get something build up, I'd be looking at the cheapest hubs with sealed bearings, stainless steel spokes, Mavic rims. Alistair Gow's Wheelcraft shop in Milton of Campsie is the best purveyor of wheels in the Glasgow area. Big Al will give good advice.