If you want something done right...

...you gotta do it yourself. I started dual-boxing a Paladin tank and Druid healer in RDF heroics, alt-tabbing between them to use abilities and its been going great. Took me about 3 dungeon runs to get used to it but afterwards I've had no wipes or deaths, no one can even seems to notice I play both characters (or they do and just don't care). So far I have been able to do all RDF hc, FoS/PoS/HoR/ToC 5 (normal) and FoS/PoS/ToC 5 (heroic). Still didn't unlock HoR HC on druid but I'll probably be able to clear that too.

I've done this once, usually dungeon groups are so slow you can dual box and still play at their level

Well, how it goes, we will all need to do multiboxing xD