20 caliber barrels, looking for advice

[Little Dutch]

Here's the order if anyone is curious:

Configure Your Custom AR-15 Barrel
Barrel Steel: 416R Stainless Steel
AR Barrel Length: 20" [+$20.00]
Caliber & Twist Rate: .199/.204 (.20Cal) 1:11 Twist 3 Groove
AR 15 Chambers: .20 Tactical [+$50.00]
AR Gas System: Rifle Length
Gas Block Journal (Length): 1.92" Long Gas Block Journal
AR 15 Contours: SPR .980, .850, .750GB, .730 (Up to 24")
AR Muzzle / Crown: 1/2"x28 Threads (.20-.224), 11? Crown
Finish: Polish


I got dies and bullets ordered last night as well. I think I have a rifle length gas tube somewhere and probably have a .750 low profile gas block in a box. I have a 15" handguard, but might want something longer / different depending on how it looks with the 20" barrel.
I will need to figure out a suppressor for it. I don't have a spare .223 suppressor to put on it, and I imagine a rimfire suppressor is going to get eaten.