Upgrade-wise, you'd probably do well to convert the hop up chamber to a VSR style one using the King Arms/2Roy parts. It'll allow you to take some really nice VSR style buckings. Tightbore? I'm pretty sure if you have the money most people would recommend an EDGI.
And as for other upgrades...if you're willing, and you really really want to push your accuracy, it's time to start thinking about an external rig!
That will all run you...hmmmm...about $200 for the TBB, bucking, and conversion, plus the rig if you want it, so if that's a little over your budget let us know so we can post you some alternatives.
EDIT: BTW I work with KJW M700s, very similar but some subtle differences, so take my words with a grain of salt!
And as for other upgrades...if you're willing, and you really really want to push your accuracy, it's time to start thinking about an external rig!
That will all run you...hmmmm...about $200 for the TBB, bucking, and conversion, plus the rig if you want it, so if that's a little over your budget let us know so we can post you some alternatives.
EDIT: BTW I work with KJW M700s, very similar but some subtle differences, so take my words with a grain of salt!