If you are wanting to play it extra safe (which is what I'd be doing) then go and speak to the tuner and see if they will book a dyno slot for you, but if the initial baseline test looks good and you are happy with it, agree beforehand that you have the option to stop there and only pay $x i.e 2-3-400.
A decent chunk of the work of getting it tuned is setting it up on the dyno, checking everything is working fine etc.
PBMS are a good bet I should think, personally I used E&H motors to tune my standalone ECU and I'm very happy with the results. Karl Ruiterman has a lot of experience with subarus and used to be the only option in Pukekohe until PBMS got back into tuning.