fresh cow manure or mushroom compost in hugelkultur?

I am putting in my huegelbeds. The first one I didn't use any soil amendments. However our soil is awful.
I thinks of buying some stuff. Our landscaper sells cow manure, but at this time of year it is fresh and mushroom compost. I have put in the woody layer, lawn clippings and some of the soil.
if I use fresh cow manure (if this is good at all) do i put it as top layer or underneath? This bed will be tomatoes and either greens or beans.
What about residues in the mushroom compost? And is it very alkaline?

If you have to buy, buy both.  Manure and mushroom compost are both non-chemical (if they don't have a bunch of chemicals in them) and it is well within the Ethic to utilize them both to make soil. 

In my Huguls I used compost from fescue seed hulls (local seed cleaner).  This has been fantastic!  Point is, the more you can put in there the better.  The fungi and bacteria will do the rest.

If you put it in fresh this time of year to use in the Spring it will be ready to go by then.  I put fresh manure in my hugel beds and plant immediately in soil placed over the manure.  I've seen some evidence of soil imbalance but nothing horrific.

So are there a lot of chemicals in mushroom compost or manure? I have seen lots of warnings to other gardeners to watch out for chemicals in mushroom compost.