Ok so first style at this, my current character is mercenary themed, so i thought Id post the idea I have for him;
First; background
A mercenary whos wandered the waste, served as a bodyguard in New Reno (He/shes been there) and when arriving in the Mojave, changed his career into a much more successful feild, well as successful as a job which gets you shot in the head can be.

Basic stat theme:
You want:
Guns and/or energy weapons. survival, speech and barter are high priority too.

Apparelel: always light armour. Leather armour, especially gecko backed reinforced is a good choice for mercenary armour.
Weaponry: a handy shotgun or the special laser rifle whos name I cant remember (Its in vault 22) along with a melee weapon of your choice, some plasma and pulse grenades and
Perks: all perks to do with light armour, other than that its your choice, after all, mercenaries have no real distinctions

Side with: for this one im not too sure, perhaps some suggestions? Im currently thinking you side with house/ yes man.