I would hold out for a anzio. If you get a 14.9? Caliber, now you are extremely limited on where to get ammunition or components. Plenty of 20mm Vulcan components available, along with reloading dies.
1. "I would hold out for a anzio." - your #8 post says they are not producing, so seems no option.
2. Conqueror - what 14.9?
3. "...14.9? Caliber, now you are extremely limited on where to get ammunition or components." Ammunition is non-existent, whatever WTC is working on its a wildcat. So, unless there is some company out there "commercializing" that chambering, its all a matter of "building your own" ammo.
3. "Plenty of 20mm Vulcan components available, along with reloading dies." - ah, TBD. Kind of depends on what the cartridge actually is. Brass is not an immediate issue - they already have a quantity of that (bought it from me). And WTC will very likely be providing the dies, which will not be 20mm Vulcan of course. Primers, other than 50 cal - which I understand they are not using - are TBD. CDVS is "out of stock" for percussion and they not going electric, last I heard. In any case, primer consistency (as in works properly for their setup and is available in same lot) is very TBD. Powder has been the problem from day one - while various surplus powders may go in and out of availability, getting enough that in same lot and actually meet the owners needs, that is a whole 'nother matter. This NOT a project for the faint of heart. Bottom line, "plenty of" is not in the same neighborhood with reality.