I've found some women really enjoy sucking cock, it's almost like a fetish with them. Others won't do it for all the love and/or money in the world.
As far as receiving, I prefer it if a lady can use her hands. As long as it's wet and slippery, her hands give her better control, so then I can just relax and pump - literally fuck her mouth - and I don't have to worry so much about potentially hurting her.
I'm not into gagging or vomit. Please don't puke on me!
If she can go balls deep without gagging, that's what I call talent... But deep throat isn't necessary. If she knows how to use her hands, she can create the same sensation without it having to go so deep. Of course, if she can do both, that's wonderful...
As far as position, I like to lay on my back, and have her lay on her side, with her head on my stomach. In that position, she can grab my cock with one hand, and my balls with the other, maybe stick a finger in my ass if she's up for it. At the same time, I can hold her head with one hand, and reach behind her with the other to make sticky fingers. It can be fun to hold a vibrator on her clit while she sucks too.
It's very submissive... She gives me all three holes at the same time.
Of course, don't stop until lil' Johnny is completely drained, and if she really wants to impress me, she'll thank me and tell me she wants to eat like that everyday...