When are you planning to travel?
You should spend at least 2 days in jaipur.. remaining 2 can be planned in another place like jaisalmer if winters or udaipur
I don't recommend to go to Rajhstan at this point of time as it's too hot over there. Winter time is best time to go. Last winter I was there for 14 days. As per my experience, I will suggest you to cover Jaipur, Jaisalmer, Jodhpur.