I've always liked the idea of playing a tribal (i.e. White Legs) kind of character. Doesn't really fit in with the whole Mojave courier thing, but still...
Melee, Sneak, Survival, and mostly the nature perks (even though most aren't terribly useful). Chance's Knife ASAP, good luck with the cazs. But Melee over Unarmed as then you'll have throwing which will work well with poisons. You won't be a power house, but you might survive.
I just started a cowboy character who's a bit of a survivalist. I'm using JSawyer's mod (which is like harder hardcoe with half the inventory space). This is more or less what I'm doing with the build:
Skilled and Wild Wasteland
Guns, Survival, Sneak
S 5
P 5
E 6
C 3
I 8
A 7
L 6
All implants except Charisma and Monocyte
2 Intense Training (Endurance)
4 Light Touch
6 Toughness
8 Cowboy
10 Shotgun Surgeon
12 Silent Running
14 Toughness
16 Better Criticals
18 Strong Back
20 Hand Loader
22 Jury Rigging
24 And Stay Back
26 Tunnel Runner
28 Pack Rat
30 Travel Light
32 Finesse
34 Thought You Died