Good Bolts-
TechtT L7 - 50$ (8.5 grams)
NDZ Skeleton - 50$ (10.5 grams)
Both are the lightest bolts avaliable for the Ion but the L7 is the lightest one ever made but there shouldn't be any real big difference between the two
If you're gonna buy a bolt you should also get a QEV...it helps you save a lot of air and reduces dwell and its only 20$
For triggers its all based on the feel and personal prefrance
CP and NDZ make really good triggers
Heres a link to Ion triggers
Ion Triggers at ActionVillage.com : Paintball