G Force

I have 03-05 r6. I'm looking to get a 2nd hand carbon fibre akrapovic exhaust, as I've read in a few places theyre the best one to buy? Am I making the right choice? How do Scorpion and arrow compare in sound? Which would you recommend?

I wanna get an 03-04 plate r6 and i have absolutely no idea what their common faults are. what should i look for? im not a total noob in buying and selling, its just that i am pretty clueless about the r6. what should i ensure that the bike should have as part of its service? im looking at one currently and there is like 4 owners on less than 7k mileage. should i be put off this? is there any common gearing problems, bad idling, coughing etc problems i should be on the lookout for if and when i go for a viewing? cheers for your help!