I scored a used set of 8 off MBWorld for DIRT CHEAP.
Keep watching the For Sale section. These came off a 2006 E55. MB went with bigger injectors in 2006 the earlier E55s use the same injectors as the SRT6.

Those guys are upgrading their injectors over there, keep an eye out.

SRT6 replacement, late 5.5L SC AMG, light-blue: Bosch 0280156304. MB 1130780123, 44-45 lb/hr @ 3 bar, 4-hole.