In reply to Fredt:
Thanks for suggestions everyone, I have spent some time looking into them all, and then yesterday I was given a Vango Artemis 500, which seems to tick all the boxes. My only concerns is that it looks huge, (4.5m long and 3.3m) wide, for two people, but this may be an optical illusion as it completely fills my small garden. However, I note that a lot of the above are similar size. Also it is very heavy with the steel poles, I struggled to carry it from the car! It certainly has the headroom and large porch.
I think I can live with the downsides given the cost, but I shall certainly keep an eye out for anything slightly smaller and a lot lighter.
Thanks again for all the suggestions.