When I first came to Qatar before I got a car I used these guys who were both very reliable and have decent cars (Chevy Caprice).

Ahmed 5496293
Mohammed 5546096

In terms of cost from Al Sadd to Park House is about 15-20QR. But you can negotiate a cheaper weekly rate. Of the two, Mohammed speaks the better English but if I were you I would try both. Really good guys and they never once let me down.

As far as licensed restaurants, I agree with Butterfly but would also recommend the Asian restaurant in the Marriot which I find to be very good.