A freak will serve you proud, and you can switch the back piece if you change marker, without having to buy a whole new set of barrels. My only advice on SP barrels is not to get the tear-drop/tear-drop freak front, they are a complete nightmare to clean if you get paint on/in it. I am currently shooting a cocker freak kit with the Freak Junior front, I have no complaints at all with either accuracy or cleaning.
Though any adjusable barrel kit will give you the same paint-to-barrel match that is so prized by freak owners everywhere; e.g. Powerlyte Sceptre, Evil Pipe, Empire etc.
But a couple of cheaper barrels will serve you well if you haven't got the cash to buy a full set up front.
A good barrel will make a huge difference, even to a cheap blowback, it is well worth the investment.
Richard