Fruit growing in a polytunnel

Hello.

I have just put up a polytunnel (10x20ft) which will mainly be used for seedlings, peppers, tomatoes etc. But I'd like to have a couple of permanent residents as well.

I was thinking of growing a vine (there are roof bars) but I'm not sure I want lots of eating grapes (and I don't want to make wine), so I'm looking for other suggestions.

At the moment I am thinking Blueberries, gooseberries or dwarf nectarines.

The polytunnel is unheated and we are in Southern Snowdonia which I think puts us in Zone 9b. Anything we grow would be in a large pot.

Suggestions?

Simon