The large number of drivers and the slightly higher than 4ohm impedance results in most of the 500 or so watt micro heads to probably not be enough to really pump the volume and make that huge cab worth hauling around. If you had a 4ohm 410UL, I would suggest the Markbass F500... fantastic, punchy, tight, clean, articulate tone with that cab. However, with the 610, not so sure.
The Genz Benz Shuttle 9, while not sounding anything like 900 watts to me at 4ohms, still seems to put out more volume than most of the micro's, so that might be an option for you.
The Markbass SD1200 is getting good reviews so far, but I haven't heard it. I HATED the Markbass SD800 and LMT800/LM800 with the Epi UL cabs... not enough low mid punch, and too much upper mid gank. However, early reports are that the voicing of the SD1200 is more even and punchy (like the F1/F500). If that is the case, that would probably kill, putting out about 1000 watts into that cab at 5.3 ohms.
Another solid option is the Carvin B2000. It is larger than a micro, but still quite lightweight, and based on my experience with the B1500 (which the B2000 replaced), it is a good match for the UL's.
Another powerful, relatively lightweight head is the iAmp Pro. However, the deep, wide voicing just didn't seem to mesh very well with the UL... lots of boom, not enough punch.
So, if size is key, and you like it a bit tight and bright, the Genz Shuttle 9 gets good reviews. If you need the big bang, either the Markbass SD1200 or the Carvin B2000 would give you massive wattage and still weigh not much more than some micro's.
The good news is that Musician's Friend has a no questions asked return policy on the Genz and Markbass stuff, as does Carvin for their amps... so very little risk to try one or all of these.
IMO! Welcome to Talkbass!