Heya, I am using this one now. Its not nessecarily perfect but I dont like to be tied down to the choices of one ui package. My experience is that the basic setup is easily updatetable by just downloading the latest updates of the respective packages, however you are ofcourse as mentioned dependant upon the packages to be updated.
Now I donot know very much of how updates here work in relation to the ui but since very little is added to the ui in general (apart from fishing and appearance slots, maybe also enhancement slots?) I think that even if out of date it shouldnt be too much of a prob, but thats just a wild guess.
If however you run into problems then switching to another ui part (of a ui that is updated) or going to the default part is as easy as opening the program (can be done while in game) selecting the part you want, save your changes and ingame type /reloadui. Some things will require restarting the game, but not much. This is also a handy feature to test out different things.
Bruzik