If weight is a factor and $ is not as much of one, I would suggest 2 410 RM EVO cabs. They are 45 lbs each and the 610 is 112lbs (some places list it at 124lbs). I use them and a pair of 210 RM EVOs. They sound fantastic.
Too bad I only have a Ampeg PF 800 Top, marked at 4 ohm. I can't run two cabs with it it seem.
Thats why Im looking at a really cheap Ashdown RM610-T EVO cab.
Just run it mono.