You can use a shield and Evasion at the same time. The only checks are light/no armor and less than heavily encumbered. That means all you have to do is replace your armor bonus, which I assume is at least 13. There are some obscure named light armors such as the
Parasitic Breastplate that come close, but the lack of flexibility for things like Incite or Heal Amp might push you towards bracers or various other epic non-armor items that only get up to 8.
I don't know how your various Max Dex Bonuses shake out, but since you'll still be using a tower shield it seems unlikely that it would go up much if at all.
Using a shield will turn off your Wisdom bonus to AC, so in terms of raw AC you'll almost certainly be behind. However, you could conceivably have the option of an AC mode with just the Fang (or a THF weapon) and a Wis item with robes and a damage reduction mode with the shield and some other item with whatever light armor or robes, and crucially you would have Evasion in both cases.
I also think you would end up with more HP the monk way: the two monk feats can each be spent on Toughnesses, so you gain 44 from that and lose 4 due to base dice for a net of +40 over the Paladin.