New iPhone, which provider

[Matblack]

I'm getting a bit fed up with my 3GS and Heather would like an iPhone so the ideal solution would be to buy into a new contract.

However I am stuggling to work out which provider to go with. I've always had a soft spot for Orange for some reason and Heather is on Orange. I won't get much of a loyalty deal from O2 because I never go over my minutes and I'm not a big spender I also want an 18 month contract because I don't want to wait too long for the iphone5 (although I understand its likely to be delayed which is why I'm considering my options).

The things I am wondering

Which public wifi hotspots can I use within the standard tariff (likely to be the lowest tariff) I can use some BT Openzone ones at the moment, are the Orange ones the same?

Does the iPhone 4 aerial probem actually exist?

Opinions?

MB