You want good accuracy, then get a barrel kit to match paint/bore. Only way to achieve higer accuracy and consistency with paintballs. Freak Jr. might be the cheapest kit to start with and once you get the inserts you can upgrade to either the full freak, deadlywind kits and all of the various fronts that can be added to the freak backs. As far as length, if shooting HPA no more than 14", if LP (I don't think you will be but who knows?) then 16" is the max.
Since you said you play front/snake then look into maybe 10" or so, would allow for maximum ball acceleration with at least 6" of stabilization. BTW I use a 6" freak insertable barrel on my main marker (not the vibe, sorry
) and it shoots fine enough for closer play. Have a CCM barrel with two sizers on the way though for my vibe!
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