oozish, It depends on what kind of blues. Both packs have some decent clean to mid gain stuff (3P, /13 FTR in pack 1 and Little Walter, Vibro King, Victoria in pack 2). There's a little more variety in Pack 2 I think so I'm leaning more toward that for you.
As far as possible amps for another pack, I'm making a mental (and now written) list based on things I want to have and your suggestions: Hiwatt, Orange, Marshall offset, blackface Super Reverb… ??
Pack 2 purchased. Amazing job! I would buy anything that moves to nail the SRV sound if you could include something like that.