I'm not big on adding just topsoil myself. Compost and manure combinations are the way to go - which isn't an option in your case.

Planters mix, Tri-mix, and Alpaca and Topsoil mix is out - so it would be between Topsoil and Cow Manure or Lawn and Garden for my picks.

Here is a link that might be useful: BsnTech Gardening Blog

So my contactor recommended a garden mix of 50% topsoil, 20% compost, 20% Cow manure and 10% humus. I guess perhaps he's not getting it from the place I thought he was. Anyways I think I'm going to go with that. If I need to amend it later I will, I think this will give me a good base (plus this way I get both compost and manure).
Thanks!
T

I built a 5 x 20 raised bed last year. Local soil is heavy clay, so I filled in all but the upper 6 inches with good topsoil and then covered it with 6 inches of Mel's Mix (equal parts peat moss, coarse vermiculite, and mixed compost)