I have a local performance shop that will make a custom dual exhaust for $800.
That is a full cat back system. I already have a semi-custom exhaust with RL Y-pipe, high flow resonator, and magnaflow mufflers.
I am looking at this as a sound experiment, and maybe a couple more hp in the higher end.

I am trying to decide on the following:

1. Exhaust tubing size - do I keep the factory 2", upgrade to 2.25", or go to 2.5" like the aftermarket G kits. Maybe start with 2.25 then go to 2.5"

2. H-pipe or X-pipe? Any mustang or truck people want to weigh on on this?

3. Single X muffler in the middle, then straight out the back?

4. Aluminized or stainless? Would be $200 more for stainless

5. Limit drone while keeping a good sound? Tubing size, resonators, mufflers, etc. This should sound similar to a G when finished.

Any other considerations?

If I like it, I'll sell the exhaust I currently have. If I don't like it, I'll sell it to someone else.
Good idea or waste of money in the general population's opinion?