Now that I've had a chance to test it, I thought I would reply to help out anybody else who is thinking about chopping their barrel.
I wasn't really worried about stability in a 3.5" barrel since NAA revolvers seem to handle it out of a 1 1/8" barrel. I WAS worried about 3.5" having enough back pressure to reliable cycle a Victory with cheap bulk pack ammo WITHOUT the suppressor. I can confirm it does, it least with my gun. My Victory reliable cycled bulk pack ammo with and without the suppressor. With the suppressor, it also appeared to keep the same cheap ammo subsonic as I heard no sonic cracks through 500 rounds. I definitely heard a few cracks with the 5.5" barrel and suppressor installed. My end goals were the subsonic speeds and improved balance with suppressor installed. I am happy with both.
For those interested in the details, I ended up using ADCO (adcofirearms.com) to chop/thread a plain 5.5" barrel I bought off Numrich. I also had them reinstall a new front sight as well. The bull barrel and tall sight combination make the sights very usable on a rimfire sized suppressor. I still have my original 5.5" threaded barrel so I can swap back and forth as desired.