Carvin BR series are well made, come in the exact configurations you are looking for, AND you can get them in quite a few colors to add to the cool factor. They aren't too expensive either.
Now, as for heads on a budget do yourself a favor and check out old Fender PA100 or PA135 heads. They can be had dirt cheap and actually have 4 separate channels that would make switching back and forth from URB to bass guitar a breeze. It's not for everyone but well worth a look for inexpensive tube heads. And by the way, a P bass sounds crazy good through it and it takes pedals like a dream. And you can daisy chain channels to add gain. I even changed out the input resistor on a couple channels to add even more gain for different personalities for each channel. Might not be your thing but that's OK too.
Oh, and Welcome to TalkBass!