http://sex.sofeminine.co.uk/sex-sexuali ... 52536.html
As for if you want to get the positions you're trying out to work, well I honestly can't tell you, because of
A. lack of personal experience
B. I don't know all the details so it may be a communication issue.
C. Maybe they're just not for you guys. Different strokes for different folks.
With a guy-
With one guy I was with I was the top, I like to start off with doggie as I can do some deep thrusting as my lover gets use to my length and thickness. I find the view erotic as I watch my penis thrusting into him and hearing him moan in response. I will then get into the missionary position so I could kiss his chest and neck. He would play with my nipples which would cause me to cum very quick soon afterwards.
My current guy (we'll call him Jacob) I have been the bottom and my favorite position is doggie with me right at the edge of the bed and him standing on the floor. I can just relax and enjoy his powerful thrusts building himself to orgasm. When I topped Jacob, I was in the missionary position with him. I could suck on his neck and nipples as I would relax a little between thrusts as not to cum too quickly. I am flexible enough also to bend at the waist and suck Jacob as I did some thrusting into his very tight ass. This just drove him nuts.
There has been an occasion where the guy is too long and a certain position like missionary was too uncomfortable for me to take the entire length of the guy. So doggie would solve this problem.