Let me get this straight...you want two 6 irons?
Clubhead selection is one thing, but the shaft is far more important.
I went with the combo set 5, 6, & 7 in T350 and 8 thru gap in T200 with KBS Tour Lite shafts. I prefer a bit higher ball flight with my irons, and want my short irons to drop and stop. My fitter was able to accomplish what I wanted with the shaft selection. Completely happy with that setup.
It's not a decision you should be guessing at, and I highly recommend having a true club fitter assist you. I know you say there is not a Titleist fitter in you area, so I suggest expanding that area. It is well worth a trip when you take into account the cost of a set of irons. And don't just go for a fitting with the intent of getting new clubs, or a few extra yards. Talk to your fitter and let them know what you are looking for in ball flight and feel, as well as performance.

The clubs are $200 each and a Titleist sponsored fitting is $100 that can be applied to a purchase for any club fit that day. I’ve learned the last person to take advice from is me. The mixed set is all about the gapping and how the ball lands (can the descent hold a green). If you trust the fitting, they will if and where you need a mixed set
Yes, I do have 48-7 T200, 6 iron T350, and then metal woods. But I let the fitter make the recommendation and why he thought this was best.