There are adaptors for E to P/C series Surefires so you can use any of the P60 heads and drop-ins. I just recently made a lego light using one of these from Tnc.
G&P head
R2 drop-in
Tnc adaptor
E2D body
Z57 tail
E2DL on top and R2 drop-in below the lego for size reference