Ultralites are always a strong contender
start off with a .692 back, dont get the standard bore (.688)
then if you want some more flexibility get the .688 and .695
or get the REDZ kit as suggested.
is it just me or does the idea of a SP barrell on an eclipse marker just not sound cool?!
(disclaimer: no diss to the SP freak im sure they are worthy barrels )