Check the wiki for the strength requirements for the weapons that you want to use, some of the better melee and unarmed weapons have some high reqs.
Another suggestion is to check out J Sawyer mod, it fixes the perks so that you can take melee or unarmed in order to take the perk. With this you can take Ninja (which is fixed as well) with unarmed 80 or melee 80. It saves you from having to max out both skills in order to get the good perks.
For stats I like
7 Str - with implant you get 8 and then +2 from OWB
5 Per - with implant you get 6 to qualify for better criticals
7 End - with implant you get 8 to qualify for perks
1 Cha - no reason not to have as a dump stat
6 Int - gets good skill points, qualifies for educated perk. Also lets you take light touch perk at level 2 if you tag repair Could lower to 4 and still work if you take skilled as a perk
7 Agility - with implant you get 8 to qualify for perks
7 Luck - with implant you get 8, 9 with LR bonus, 10 with lucky shades. Crits are you friends, also with luck this high it is not gambling, it is guaranteed
A high crit sneaky light armor ninja has very nice synergy with energy weapon use, specifically lasers with laser commander. Throw in fast shot and built to destroy and you will be devastating with energy weapons as well as melee or unarmed.
With the above set up and JSawyer's fixed Ninja perk I get a 32% crit chance with melee or unarmed without taking into account any bonus from lucky shades, 1st recon beret, Joshua Grahams armor or the light touch perk. With those bonuses it goes to a 41% base rate. With a katana you get 82+5= 87% critical rate at almost 6 attacks per second. With unarmed I'd look for the fist of rawr or the embrace of the mantis king for an equally high crit rate.
Chainsaw type weapons also check for crits many times per second and are silly powerful with a high crit rate.
Some people suggest to go the low luck heavy handed with explosives path but I really like the super high crit way for melee coupled with energy weapons.