We have no family around us and when we had our daughter (17 yrs ago) we continued weekly date night because it was a priority in our marriage.
We had references for high school or college girls in our neighborhood, word of mouth is a great way to get a good one. We guaranteed $40 for the night and then added per hour on top of that and paid cash. Each week our sitter was $60-$80. We always had a good sitter because they liked the pay.
Move ahead, our daughter is now 17 and she has been sittiing about 3 yrs. She averages $12-$15/hour cash. She does not sit on her behind... she is active with the children such as arts/crafts, mani/pedi, this holiday season she took gingerbread houses and they made them.
When you find a good one, hold on... People pay to keep them.
The average pay is $10/hr. My daughter has never set rates, she is glad to accept the jobs because she loves the children.
Another source is a mom's group, your church,preschool, school, teacher's high school children, etc. Our neighborhood has a secured website and babysitters can advertise on that.
Good Luck. It's too bad your family feels like you are asking too much. It is not like it is weekly and gees... those little ones will be grown before they know it.