I think it would be more realistic to add at least 5 pounds to your minimum if you want performance cabs. Having said that, I own 2 x Eden EX110's 8 ohm cabinets that I use with a GK MB500. I've recently played some pretty loud jam sessions and the two cabs and GK have not even strained. It's hard to believe the cabs house a 10" bass speaker, I just don't know how they get so much bottom end out of those little guys. They are 25 pounds.
If you go up to 30 pounds, there are the Eden EX112's, which are much deeper and will produce more low end and presence. I almost wish I had bought the EX112's but I got a sweet deal on the 110's. Eden stuff seems to be the best kept secret on TB, although you'll find a lot of TB'ers actually own Eden stuff. Very high quality made equipment.
My other choice would be the Schroeder Mini 12L+'s. They get great reviews. 20 pounds. Jorg even has a Mini 10L+, which is 17 pounds and handles 300 watts per cabinet. A couple of those would rock the house!
Here's a generic pic of one of my two bass cabs, Eden EX110's.
View attachment 2852467
EDIT: The Eden cabs are so light and easy to move, when I show up for a gig, I carry one in each hand. They have big comfortable round handles on them for easy transport.