Hi Denise,
This may or may not be of use to you.
1. Isabella are normally regarded as making the best awnings. They are expensive.
2. Ventura (I think that the name) are made by Isabella, or use Isabella materials I can't remember which. A lot of people of these forums seem to rate Ventura awnings. They are a lot cheaper than Isabella to buy
3. NR Awnings also have a good rep. They are cost effective and made in the UK (Located somewhere up North I beleive). Available direct at www.nrawnings.net
4. Steel poles are the norm, but are heavy. Most manufacturers offer an aluminium option, but some forum people report poles bending in strong winds etc. An alternative is carbon fibre, expensive but strong.
5. 2nd hand awnings are a mixed bag, if you can find one that has only been used a couple of times and looked after it could be a good buy, otherwise best avoid?
Hope that helps a bit. (If the NEC os so far away, where about in the country do you live, in case anyone has any suggestions).