You could just go with the DR100mkII and ditch the UA-5 altogether as the DR100mkII has a pretty good pre-amp as well.
Agreed. You might also view it that we are now in a post-UA5 world too. Especially if you have only a digi-mod UA5, not an Oade or Busman analog-stage mod on your UA5.
The UA5 was great for when it came out, as it was a good, low cost solution for a 48v phantom capable mic preamp + A/D that did 24bits. And especially with the Oade and Busman mods sounded quite good.
But at this point, there are a lot more options, more options for preamps (esp on the used market with very good prices) and with all-in-one recorders that have good analog front-ends, do 24bits, and provide 48v phantom.
Giving up completely on the UA5 and looking at the Tascam DR100 mkII, the Fostex FR2le, the Marantz PMD661 (esp Oade modded), the Marantz PMD671 (esp used), and the Tascam HD-P2 (used) all would make great options for all-in-one recorders.