Warrior shields?

I'm a 190 Paladin and I've been using a junky level 90 shield because it came with +3% str. With shields getting Weapon Potential soon, what are the best options for trading up to something better?

Doesn't really matter. The higher level shields have more built-in STR, but also tend to be untradeable or hard to find or both.
Except for the Fearless Kite Shield, all 71+ warrior shields have 7 slots, and none of them belong to any sets.
Whichever one of them you manage to obtain scrolled well for attack (or to scroll yourself) is fine. 3-lined and epic or better is prefered, but the actual potential will have to be recubed once we get that patch.

Disregard this post, I'm an idiot who can't tell the difference between a Hero and a Paladin and have no idea how Paladins work.

While it's probably of little consequence, the level 100 secondary weapons you can buy using Evo World Coins (400 coins), have 2 attack more than the standard ones.

However, as the secondary weapon can't activate a paladin's shield skills, it's not advisable to use one on a Paladin.

You should really upgrade to a level 100+ shield though, as only 100+ items can gain the maximum Boss Damage available from potential, but if you're not really planning on cubing all that much, I suppose it doesn't matter. I would recommend either a Last Unwelcomed Guest Shield, Blue Dragon Shield, or maybe even a VIP shield (if tradeability is an issue, otherwise any of the 120 shields or the 130 shield have better STR boosts without scrolling), though. If you're going for static, not percentage potentials, like +atk, the higher the level the better, as unlike % boosts, the static boosts change at different intervals and continue to increase even past the 71~80 range.

my poor pally is using a +6 watk maple shield :D

I have a 3% str one, but it's still not better than the 6 attack on the maple shield :C

So it's not worth trying to find a Deimos Shield recipe if I intend to self-scroll?

If you don't care about tradeability, a Deimos Shield is probably your best option (but a Timeless Shield is potentially better, if you get enough STR from leveling it, and depending on how much above average the shields are).