The Portaflex series did catch my eye, especially the cabs. Is 350w really the minimum requirement for a band amp though? Reading around, it seems like the amount of speakers and their sensitivity seems to be the deciding factor. Otherwise I'm left a bit confused at the amount of 200w heads being praised as "loud enough".
Hah! I should have said in my experience :) It certainly depends what you play, but I've found the more aggression or musicians you add, the more power you need. Smaller amps would have cut it in the small duos and trios I have played in, but in my punk/experimental projects and the larger bands I've played been a part of, it's nice to have the extra headroom to make sure you can be heard. Sadly, it's not always feasible to ask people to turn down in those situations, and if you can't turn up you mightn't even be able to hear yourself.
You're absolutely right that speakers play a role, not only in loudness, but overall tone (and portability, as my back can attest). I think a ~350w and 4x10 cab is the "small" gig standard for that reason, but it could be total overkill for your needs. If you go down that road I seem to remember Avatar and TC Electronic made some lighter cabs with neo speakers... there are probably other options too.
I think the Ampeg could be great if you're already looking at them. Ampeg is one of the classic bass sounds IMO, and the weight of that series is pretty reasonable for the power. They seem to review pretty well too. See if you can try one in person, and turn it up a bit, it mightn't be as loud as you think. Good luck!