Splatmaster??? Skeet, that's just naaaaasty!
Get the spring kit, the middleweight springs are pretty effective at getting the velocity consistent.
Turbulence Bolt, I can't talk this bolt up enough...not sure where to get one, I got mine from E-bay...but since I fitted it the spyder puts the paint EXACTLY where you want it helped by...
12" Smart Parts teardrop barrel. I've used a 14" on 4 different spyders now and it doesn't have accuracy of the 12".
I know that most of this is all probably personal stuff, site paint, my markers, etc......but i've found these three to be the best i've done to the marker.
Oh and if you're going to get air...get an on/off ASA, i've fecked 3 o-rings so far getting my bottle off after a game...even when shooting and unscrewing