The only thing I would add to YeloSno's list are
-The .679 Eigenbarrel for use with smaller paint. I have had zero breaks in 6 months with mine, using all different sizes of paint.
-I don't know what goggles/tank you have at the moment, but consider upgrading them as well.
Also, Lurker is having a sale where you can get an eigenbolt and eigenbarrel combo for less than buying both seperately.Link to sale