What I do: have STR and END at 9 from the off, to be boosted to 10 via implants. AGI at 6, plus the implant to make the 7 needed for the Slayer perk. Rest of the SPECIAL doesn't really matter for this build I don't think. Important perks: Super Slam; Stonewall; Toughness; Piercing Strike; Unstoppable Force; Purifier; Paralyzing Palm (if unarmed, skip if melee only); Ninja; Slayer.
Skills-wise, you're basically forced to do up both melee and unarmed for the best perks, so may as well raise both to max. You're going to want to get sneak to 80 for the Ninja perk, and beyond that, any remaining skill points are probably best spent in survival or medicine.
General tips: you want as much DT as possible, good combat armour or power armour will help a lot, as will sub-dermal implant and perks. Also, chems are your friend, use them a lot.
Companions: I'm currently rolling with an all melee team of Veronica and Rex. This is definitely not recommended unless you like punching your companions to death repeatedly. I'd suggest getting Cass for the perk if you can meet the barter check, and ED-E; that team should complement a brawler pretty well I think, though I haven't tried it myself yet.