I've started using the yudane(japanese)/tangzhong(chinese) method recently and am still experimenting with this technique.

Might be perfect for your buns, particularly as it is so easy to make the dough for this with the help of a bread machine.

Alhough I haven't got to making rolls, baps or buns yet, this blogger has and if you scroll down you'll see how he/she adapted a recipe to making burger buns
http://kopiaste.org/2010/03/buns-wit...zhong-starter/