View single product from product class in a block

Hi everyone, I am a newbie and am after some advice regarding views, any help would really be appreciated.

I am trying to create a block view with certain products from varying product classes that have 6+ products in them.

e.g Product class A - 6 products
Product class B - 12 products

I have created a view that uses all 6 products from product class A and all 12 products from product class B into one block but thats not what i'm after. I would like 3 specific products from class A and 6 from class B. I have tried filtering by nid, successfully filtering 3 products (not the specific ones I was after thought) from class A, but then after adding another nid filter for class B doesn't work. This is my view info for the 3 product filtering if it helps.

e.g Fields:

Node: Title
Content: Image product_list image linked to node
Product: Sell price Price
Product: Add to cart form

Filter:

Node: Type in A & B
Node: Nid between 136 and 138

I have also tried filtering by ubercarts SKU but to no avail. Is this possible? I don't really have the best understanding of views yet but have been tinkering about for hours now trying to get this to work but am having no luck watsoever so any ideas/advice on how to achieve this would be great.

Gillypots :)