To be honest, the concept of sharia banking seems to be an absolutely ludicrous concept. Yes, there's no interest, but often it's replaced by a monthly 'fee' which basically amounts to the same thing as interest anyway. It's a pure case of calling one thing by two names.
Within my own country of Britain, there's the Islamic Bank of Britain and also a sharia account ran by Lloyds TSB, as well as some others. I have a flyer for the Lloyds sharia account and this is approved by 6 different sharia experts, but is purely limited to current accounts, business and student accounts. There is little option for sharia-compliant mortgages or other forms of finance, and as far as I can tell, only the Islamic Bank of Britain offers anything like this.
As to the issue of Islamic mortgages, I looked at this and a typical scheme is more expensive for everyone concerned, as you say. Usually the way it works is that you essentially are on hire-purchase, where the amount you pay covers bank costs and also increases your share in the property until the point where you own the property in its entirety.
I've certainly seen Muslims with ordinary, interest-paying, debit and credit cards, and going to non-sharia banks for their money.
With regard to your question about the Hajj, I can't understand it either. One credit card (yes, a credit card,which again has the issue of interest) has started putting Qibla compasses on cards to help Muslim customers find the direction of prayer, which to my mind seems highly contradictory too.