birth control after 2nd child

I have 2 questions:

1. We just had our 2nd boy. Our two children are approximately 18 months apart. We very much want to go on some form of birth control, but only if we can find a reliable heter. I keep telling my wife that we should do research before asking because once we ask, if the answer we get is that we may not go on birth control we cannot disregard that answer. Therefore, my question is: What is the best way to go about asking a reliable rov, but one that we are pretty sure will give us a heter.

2. Assuming that my wife is on birth control, is mutar in ANY WAY for my wife to make me ejaculate while not in her vagina? The logic is that since our tashmish can't lead to p'ru ur'vu anyway maybe there is a heter for some form of hotzaas zera levatala. Of course, I understand that that that logic proabably doesn't make it mutar but it's worth asking.

Thank you very much.