Have just recently returned to WoW and are 5 boxing (Prot PAL, Resto SHA, 2x Arcane MAG and Destr WRL) and have been doing the MoP Heroics after getting the toons in next to full timeless isle gear.

With that gear level (496-500) I havent found any of the heroics that hard as it have been possible to "ignore" many boss mechanics and just burn/heal thru. Sure some of the mechanics are still hard but it is much much more forgiving than I recall from trying them in quest blues and greens.

Doing them in the charachter boost greens shouldn't be any problem but install the TomTom addon and paste in the timeless isle chest lockations and do the run and you should get plenty och new pieces for your team.