Personally, if I were going to pay for a Dyno Tune, I definitely would not use something like the Fuelpak, and I'll bet you money that it will be hard to find a tuner who will agree to attempt a tune with that particular device. The best thing to do, IMO, is first, find a good tuner. Second, talk to him/her about what kind of tuning device he/she prefers using. On an '03, you have many options, one of the simplest being a Power Commander, and generally speaking, there are a lot of tuners who are familiar with that device. Still, you need to use whatever your tuner likes and is familiar with.
Now if you're just talking about getting a pull on a Dyno to see what's happening, they'll probably do that. I may be wrong, but as far as I know, the only thing a Fuelpak does is provide the capability to provide more fuel to the engine at various RPM's. I assume you have talked to V&H and gotten their recommended settings for the Fuelpak and your exhaust/intake setup? That will get you close, but won't get you a cigar...
Hate to tell you, but to get a GOOD tune, you're going to have to spend some more money.