General service is at 4.5k miles but there are aditional items to be serviced at some intervals. Are you looking for itmes to service yourself? if not you would be wise to speak to an evo specialist to deal with the servicing.
If I were you I would ring around and see who has the best price available. There are several service points that only a specialist should undertake but the rest i.e Oils and filters, brakes and coolant can easily be done by any grease monkey.
I personally think that I give the best deals but you would need to take fuel into consideration too