The nice thing about getting a lunchbox is the different choices it will afford you. After getting a all-around preamp for vocals, you could add a Neve-ish, a P-1 or EM Blue, an api-ish, or something dark to calm down bright mics. Check out the Eisen Audio site. He can custom build you whatever you want. He recently tweaked a Lundahl preamp for me, beefing up the low end and making the high end darker - which can be really helpful on a bright singer.
Just like having only one mic could be a limiting factor, likewise having only one flavor of preamp could hamper your creativity when trying to match the gear to the source.
"You're either with a native DAW, or you're with the terrorists." G.W. Busch Lite