Well to answer to the first part of your question where about do we have good North indian restaurants ....i am sorry buddy we dont have any, however there are certain restaurants that i can strongly reccomend check them out may be it suites your taste

1) Tandoor....near Doha airport

2) Swagat...Najma street

3) Bukharas

and also i can recomend a paki restaurant to you they have some good north dishes its called Quotba its in mansoora near Apollo clinic....

Njoy and Bon Appetit