At first, I was going to make an Archer like your second build (2 Str, 1 dex, 2 Luck). But I've decided to follow Phoenixsoju's and Achete's advice and I'm now making a Luck build (1 Dex, 4 Luck).
I won't lie to you, it's very, very hard. I'm leveling much slower than everybody else and my normal damage and defense are pitiful. I'm sticking mostly to 'dark blue' named mobs because most 'green named' mobs are too hard for me.
However, I've just reached level 14 and I'm starting to see my criticals kick in. When I critical it's wonderful (I'm doing as much damage as a mage
I'm still not criticalling as much as I'd like, but I'm really starting to notice it when I do. I can feel myself getting more and more power as that Luck stat increases.
But yes, the Luck build is a nightmare at the beginning, but I think it will pay off in the long run.