My little Gohma is your typical female rat. She's everything I was expecting from getting a girl rat... Hyper, hates to be held, and rarely scent marks.
Dust is hyper too, but she tolerates being picked up, and loves to cuddle. She's on my shoulder cleaning herself right now.
It depends entirely on the rat itself. If you want a cuddle-bug who is also hyper, I'd say try to find a girl who shows no desire to get away while you're holding her. That's why I chose Dust in the first place--because she didn't seem afraid to be held, even though the pet store girl picked her up by her tail.. She didn't like that, of course, but once I was holding her the right way she calmed down.
If you just want a cuddler and nothing else you're probably better going with a boy rat.