build questions (thinking about 2 uppers)

[sharps54]

Hi, I'm pretty new here and have some questions about my .300 build(s). Over the last few months I have been thinking about getting something bigger then .223 in an AR platform for hunting here in the southeast (mainly NC) and have decided that I want to go with a .300 Whisper (or .300/221, .300 Fireball, ...) because I can use my existing magazines and brass. The other contender was 6x45 but for the woods I'll be hunting in I think the .300 makes more sense.

So what should I be looking at in a dedicated hunting upper in this caliber? In NC I can't hunt with a suppressed weapon (although I can here in VA) so I that isn't an issue. I was thinking 16" barrel, carbine gas port, 1/10 twist, flattop upper, folding BUIS, Daniel Defense Omega handguards, Vortex FH, and an undetermined low power optic. I am thinking supersonic 125, 130, 135 grain bullets for this, mainly hunting deer and hogs. Any comments would be appreciated, for example is there any advantage to a longer barrel, different twist, should I be looking at heavier bullets, etc.

I also am interested in playing with this round in a suppressed barrel but I was thinking about building a seperate dedicated upper for that. I was thinking 11.5" SBR, pistol gas port, 1/8 twist. Any suggestions here would be appreciated keeping in mind this upper would be pretty much for subsonic loads only.

My last question is chambering. I noticed in a response to Cold's post there are some differences in the different chamberings (.300 Whisper, .300 Fireball, .300/221) and I would want to use the same one for both barrels. I would rather not deal with SSK so I guess that leaves the "wildcats" as my choices, any reason to pick one over the other?

Thank in advance!