Candlepower Forums is your friend, here. Go and ask the question.
I'd guess you'll be told:
You *must* have the ARC AAA (I think it's compulsory)
The E2e is a must have, but you need the KL1 head, too (unless you can spring for the A2)
The Inova X5T is also pretty compulsory
You *need* a couple of G2s
Why not buy them all?
I don't really fit in there, being as I've only got (deep breath)
Surefire 6P (P60/P61), E1, E2e (with KL1 too),G2
Inova X5T
Photons (about 6)
ARC AAA and LS1 hybrid
Streamlight Stylus, BatonLite
MiniM*g with Opalec NewBeam LED module
UKE Mini Q40
I only *need* an SF A19 adaptor and a Turbohead for the 6P, OK, maybe a P91 assembly too, just in case)