I would probably stick with a different weight/width of Futura. Adding in another sans could be like putting margarine and butter on the same piece of toast.

Is futura condensed going to be for headers?

It could depend upon the size relationship you will be using.

At the moment I'm using Futura BT medium for the body text at 8pt and bold for headers also at 8pt and I'm getting a nice result. I may well stick with Futura there are enough weights to carry it. Thanks guys I'll try to stick up the results for you to check out thanks for your help