LCT have an MP5 coming soon-ish (it's in their catalogue as coming soon) which will almost certainly be available with their EBB gearboxes, which are pretty brutal. You don't get the usual TM refinements (stop on empty, bolt lock/release) but you will get a stamped steel receiver and decent plastics, which you absolutely won't with any future NGRS. If you don't want to wait they have HK33s with the same gearbox out more or less right now; if they make a HK53 that would accept the same SureFire fore-end as the MP5.