Custom tuning is a LOT different than a simple oil change (and seals if you need them). No doubt that push can do some great stuff, if that is what you need..... Either way, you REALLY should figure out how to do regular service yourself. The bushing lube needs VERY frequent changing and it will cost you a fortune if you pay someone else to service your fork as often as you SHOULD be doing it.
Just for perspecitve, TFT (push tuner in the UK and one of the best know general MTB shock tuner/service companies) recomends doing bushing lube service every 10 - 20 hours of use. While this is most likely overkill, it will give you some idea of the regularity of service needed on ALL newer forks (with small volumes of bushing splash oil).
All the info you could ever need to perform basic service is available at Rock Shox. Videos, tech documents for all procedures, lube types and volumes, part numbers, exploded diagrams, engineering drawings, etc.
