well a perfect white 4 socketed paladin shield could have 45 all res as an automod. with 4 pdiamonds you could get 121 all res right there. with an um in both your helmet and your armor, you'd have 151 all res, meaning that 5x 5% all res charms should do you well. you do lose the advantages from other shields tho because blocking is lower, no +skills etc.
anyhow its definately doable, but depending on your budget i'd say the safer route is to go with resists and blocking instead of dr. with resists and blocking and leech you can still dive in and play, but without resists you have to worry about being tanked by big monsters while the archers and mages pick away at you