If all your vehicles are GM,yes there is a program you can buy that will tune all of them just about from 96 to 07.
You need to have about 4k minimum to drop on it though,but you will have real time tuning available.
I've got over 4k in tuning stuffs,just purchased another 800$ and about to drop another 3k$.
You can get as deep as you want too.
No tuning suite programs every make/model though-most are brand specifc Ie..Honda,GM,Ford
With the exception of Hptuners which does GM and Ford I believe.
HPtuners is okay for personal tuning,but they're options are somewhat elementary and their real time is laughable as I understand it.
Great program,but not for serious tuners.
None of the well known tuners that I know mess with it.
Ed wright has both programs I have,but mainly uses stuff he wrote himself. Wester's uses and has wrote several files for one suite I have.
For serious tuning options check out some of Craig Moates' products,that dude is a genius and extremely helpful.
I got my first tuning suite direct from the developer when it was introduced and it's not VIN-locked.
It's now licensed by JET as some Dynamic peice of crap that is almost useless without alot of knowledge in tuning,and is also VIN locked with license's.
And a dealership can't program a pcm,it can change just a few parameter's depending on vehicle-and update the factory calibration.
The local GM dealer calls me when they need to program big wheels/tire sizes etc..
And at the local Ford dealer I'm the technician that reprograms the pcm for things like that generally-we don't have the capability to "tune" anything.