To answer your original question, if I was putting down $900, an extra $300 to ensure that I was getting something good, would be a no brainer, but as others have said, there is probably a limited market.
I bought an ISSC straight pull several years ago, I had it chopped by 100mm and a bushing made up to fit my .223 suppressor. At the range, people ask if I am dry firing.
If you could make a full length suppressed howa mini (or similar) that fired 9x19 (call it the modern worlds answer to the De Lisle), that is something that doesn't have much competition.
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