I have just bought a Carbon Art Sp50.
Can anyone thats ridden one tell me what size sail/fin they use.

I am 85kg. What size sails have will it take. I see slowboat uses 7.8's on his sp53

The sails i have are 7.8,7.2,6.7,6.2 and 5.4

The fins i have are Tech falcons 26&30
Speed weeds 26,28,30

Any suggetions on set up for the differnt sizes

Slowies the best one to talk to re fin sizes.

I've used up to 7.7 on mine with a 33 Select Devil and it felt good. The Devil is a crap fin but a nice 30 would probably be good with the 7.7. I've used a 27SL7 with the 6.0 and 6.6 and it felt great. You'll love the board.
Your fins should be ok.