I'd recommend to encrypt the swap (maybe with a passphrase instead of a random one time password, I don't trust the entropy pool while booting up). No swap at all might get nasty if you hit your ram constraints.
Well the most sensitive keys will be kept on an offline computer which presumably runs nothing else except offline Armory. There's not really a way to run through your RAM there. Plus, I'd rather run out of swap than have the keys accidentally hit the hard drive unencrypted without warning. But yes, it is possible to have encrypted swap, though I don't think you can use hibernate if you do that, so you'd be disabling hibernate which is 80% the reason you wanted encrypted swap to begin with.