This is such a long post, I don’t know if I already posted to this. Choosing a perfect bluegrass group is an impossible task since bluegrass covers a wide variety of stylistic techniques depending on whether the band is more traditional or more progressive. I like both progressive and traditional players myself, however I will lean toward progressive bluegrass players as an interesting group to put together:
mandolin; Chris Thile
fiddle: Michael Cleveland
guitar: David Grier
dobro: Jerry Douglas
I would pick Bela Fleck for banjo, but I am unsure what he is doing these days. Mostly I would like to hear those four fellows jam for a while. I think that might be fun.