I had an all Orange rig. It sounded stunning but it was FAR too heavy, more so the cabinets.
The AD200b is a nice simple powerful tube amp. Warm, with a lot of bite if you want it.
Personally, I think tubes are much more of a 6 string guitar necessity. Whilst they always sound great, I think they are more crucial to a guitar sound. A good quality solid state bass amp of say 500W with a high end gain pedal and you will get so close with a lot more headroom.
Unless I toured with a band properly again, I wouldn't opt for a full tube amp for bass.
I do however think the Orange solid state amps are worth your time. If they still made it, I would suggest the Bass Terror!