I use estee lauder double wear and really like it. I get an oily tzone too at times. And isn't too heavy.
Best thing to do is go to your local boots/department store and ask for a tester. In my local boots they keep small vials behind each make up counter and colour match you with the foundation and then give you a small sample. They did this for me with double wear - it lasted a fortnight and I've never used anything else since!
I've got and oily T and dry cheeks and have recently converted to L'Oreal True Match Minerals. It goes on like a powder but has a foundation cover that you build up to the coverage you want. It covers all my blemishes and never brings me out in spots (minerals are supposed to be kinder to your skin). It also blends really easily so I can put in on half asleep on dark winter mornings without looking like Coco the Clown! It gives your skin a lovely glow and makes my skin look far more perfect and smooth than it is - and it's cheaper than having to use foundation and powder.
thanks for both of those. i popped along to an estee lauder counter today and have now got a sample to try. will check out the l'oreal one too, sounds really interesting.