There's a place called TMS Performance in Auburn. They use a Mustang dyno instead of a Dynojet. I have been there twice, last time was just last week getting new numbers after my cam install.
It's a Mustang shop (TMS stands for The Mustang Shop). Location is about 30 mins from McChord side of JBLM and they offer a military discount. Standard price for a few pulls is somewhere around 80-90, but you can also rent it hourly which sounds like what you will want. They also let you drive your own car if you ask
But, since it's geared towards mustangs the datalogging is not perfect; they log MAF voltage instead of frequency, so you would need to disconnect their setup and hook your datalogger up when tuning, then switch to their setup for the numbers. They have an OBD splitter so you can both hook up, but it slowed my HPTuner down so much it was useless. They log spark advance though, so you can see if the computer is pulling any timing.