I'd go with the AL-1200, probably. The tube is pricey but they can easily last a lifetime, it's a very very rugged tube that resists damage even from severe cockpit error. It's also "instant on," unlike the 3CX800A7.
I don't like the Centurion at all; it is undercooled and they fail. It also cannot make legal limit power because neither the power supply nor the cooling system will allow that.
One nice thing about Ameritron is they've been in business a very long time, are well capitalized and not likely going away, and make every single part in the amp available at reasonable cost. You can buy every part in it from their website, and it's been that way for many years. They encourage self-service and won't void the warranty.
A government which robs Peter to pay Paul can always depend on the support of Paul.
-- George Bernard Shaw