I'm more of a DA/SA or SAO guy but I don't discriminate against any handguns. I'm thinking of getting a dedicate suppressor host 9mm striker fired gun. I want a factory threaded barrel because I want left hand metric threads as opposed to 1/2x28.

Anyways, the two options I am thinking are:

A used like new Gen 3 factory threaded Glock 19 that a local store has for $450 or a new VP9 Tactical for $550 from PSA. The VP9 is very attractive because of the mag promo going right now. Which would you choose and why? I have always been a Glock guy when it comes to tupperware guns (have a G19, G17, G23 and G30), but the VP9 sure feels nice in the hand, although I've never shot one. I do have a USP compact that I like a lot. Which one suppresses better? I have my suppressor on my G17 right now with a SiCo barrel and it is ok. It has some blowback and malfunctions occasionally.

My suppressor is a rugged obsidian .45

for striker fired, I would wait a month or two for the CZ P-10C Suppressor Ready model to come out. I have owned and carried a number of different Glock 19's over the years, but the CZ P-10 is a better pistol in my opinion. I have spent A LOT of time lately with the two side by side at the range and wile training. The P-10 trigger, ergos, and grip angle are vastly superior in my opinion. Right off the bat the P-10 SR model will be about $100 cheaper than the G19. To make the G19 trigger nearly as good will cost you $125+ more. Other than lots of cutting and melting, not much you can do about the luger style grip angle of the G19. I always have to adjust the front of my G19 down a few mm's because of it.

I have two VP9s, one with a regular barrel, one with a Silencerco barrel.  The threaded barrel pairs well with my Octane 45K.  No malfunctions with about 800 rounds of handloads through it.  Little to no blowback.  I'm happy with it.

These FMK pistols worth a damn for the occasional wet work?

No, lol