If you use RunUO from SVN you can download the last client and patch it to the last version.
If you use RunUO 2.1 you must stop before High Seas Adventures ( before 7.0.9.2 ) or you can't login or play corretly.
With RunUO 2.0 you must stop before Stygian Abyss ( before 7.0.0.0 ) or you can't play correcly.
With RunUO 2 RC i suggest you to stop patching at any 6.0.x.x patch.
So with any version of RunUO you can download the related client version and patch it, or you can download the previous version then patch it to the last compatible version:
RunUO SVN -> Mondain's legacy or Stygian Abyss or High Seas Adventures, then patch to lastest
RunUO 2.1 -> Mondain's Legacy or Stygian Abyss then stop patch before 7.0.9.2
RunUo 2.o -> Mondain's Legacy then stop patch before 7.0.0.0
RunUo 2 RC -> Mondain's Legacy then stop patch at any 6.0.x.x ( i don't remember the exactly compatible patch, but this RunUO version isn't supported anymore...)
So if you use SVN version, i suggest you to download the last available client then patch it.
If you download mondain's legacy client you can also patch it to the last available version, but you spend more time to patch ( because you must download and apply any patch to transform the client in all versions between you client and the last client:
Mondains'legacy-->patch...patch...patch-->7.0.0.0 Stygian abyss ( you have exactly the same client that you could download one year ago ) --> patch...patch...patch--> 7.0.9.2 High Seas Adventures ( the same client that you could download some months ago ) --> patch...patch...patch-->7.0.10.3 The last client that you can download from UOHerald -> patch...patch..patch --> 7.0.12.0 the last patch available