2 CON 1 STR - This is particularly one of the balanced build for a Paladin, not only it caters High DEF and HP but with a decent, though not so much damage. It will ease the head ache of enduring to watch your petty damage flash from your LCD screen. Honestly, based from experience, banging monsters forcing you to release skills repeatedly just to drop them dead would really get in to your nerve. You are to expect not to die that several times, unless you're a game-deaf, a beginner or an inborn lousy player with a decent damage to aid you on your progress. I'd say this is for average, casual players. Regarding the gems and equips, I’ll leave the choice to you since it depends on your play style. As for issues concerning lack of mana, go visit the item merchant.
2 STR 1 CON (My current build) - This build provides a very good amount of attack with a so-so HP and DEF, mind you this build is killable if your level of playing is average or poor. The 1 CON is there to keep you raise and secure a small rate of survivability since later in the game, every point of HP and DEF counts. You'll be able to clear mobs faster utilizing fewer potions. This build kept me progress the game very quick, mobs and bosses never did serve as a hindrance and never did I use Origin of life, though I often reload the saved game. Never had difficulty on spamming skills since your net income from killing monsters per 99 pcs mana potion usage is higher than gold spent on consumption. If you're not confident about your skills on using this build and hates dying because '****, I am so slow' then drop the idea. Otherwise, if you're skillful enough like in dodging projectiles, luring in monsters and dashing correctly, the game would be a fun place for you. This build pose a moderate challenge.