Big ups to the T45! Lots of good, usable tones in that bass!
As for amps, I play a variety of amps with lowish to middlin' power levels. Preference is a decently powerful amp turned down. I do play my 100w Peavey Century 200 quite a bit, as it gives that perfect, 70s classic tone when on the edge. The Bassman Ten is great for lower volume, too.
Also play the little TC BH250 head or the Markbass CMD121P combo regularly. These work great in 1x12" situations and are plenty loud. However, most gigs that I would use those amps are now IEM, so it's the 0w Bass Fly Rig.
If the urge rises to tote some classic, racked up, class AB amps-it would be the 95 Eden WT500 or 03 GK 400RB III.