Ampex 351 or 354 preamp is fantastic for guitar, bass vocals, keys (especially Hammond types) and overheads.
Take a look at Steve Albini's mod list for the 351 (
Electrical Audio :: View topic - Ampex 351 Preamp Modification Info!).
For an audio interface, I use the Focusrite ISA428 w/ digital card via SMUX to a Presonus Firestation, and firewire from that to a PC or laptop. I like the transformers alone sometimes. But the Ampex can go directly into the Firestation. I sometimes run the Ampex into a Fostex reel to reel before the Firestation for that real vintage vibe.
This biz is a gas for those of us with G.A.S.!!