Your father is very astute if he is a non muslim. The majority of so called halal banking methods are really the same thing and not halal in the slightest.

However there are some services which are completely islamic. Ahli bank from Kuwait has a murabaha housing loan which is completely halal. It is the same thing as a fixed loan however according to Islam the person giving the loan can calculate fixed fees anyway they choose. Also the house is in the buyers name at exchange of contracts while other halal loans wait for the end of all payments for the house to be in the buyers name.

as far as I know the only issue with the murabaha loan was the contract within the contract. Which is something haram. However because of the laws in the Uk it is a necessary protection in the non-muslim countries for both the buyer and bank.. and therefore the good outweighs the fitnah (potential harm)

If I do ever move to qatar.. I will definately keep everyone posted on the halal and haram banking methods and investments in the middle east. So keep a look out for my financial posts in the threads.