Actually, I may be able to help shed some light as this forum has been incredibly helpful in our situation as a same sex couple. (btw, love you all!)
We had the same issues being a bi-national (US/UK) same sex couple, and after looking into the options of where to settle and be together, we were able to fulfill our dreams of finally living together.
Because of the backward laws in the States that don't grant my partner any sort of rights, we decided to obtain civil partnership in the UK.
We went through the PCP, proposed fiancee process, which was a bit labourous and nerve wracking but completely worth it in the end. You do have to supply a ton of information regarding your relationship and your ability to support yourselves as you won't be eligible for public assistance.
Once you get your PCP, you can come to the UK and have you civil partnership ceremony, after which you can apply for your FLR, which we have done and were approved. That allows you 2+ years to stay in the UK (no more leaving after a few months).
You again have to prove your relationship in a multitude of ways, not a problem with us because we have a lot of friends and family write letters as well as our plane tickets, phone records, vacations together etc.
Once you get your FLR you are also able to begin looking for work, and life really starts to kick in. It has been a whirlwind of a journey but every morning I wake up and can't believe we are able to finally just be together.
If you have specific questions regarding the process, feel free to PM me and I can share a bit more info.
This post is to just say that although it may seem daunting, it is indeed possible and worth all the stress, money, and waiting.