That's all you need to deal damage, combine with DD set like Blue Wolf/Tallum/Majestic and you'll make someone hurt a real bad.
You can also go +CON -Something, usually STR. with Tank armor like Doom/Nightmare, but that is more end-game PVP set-up, I'd still go +STR even in PVP though depends on your situation. It's horrible for PvE, really low damage compared to the other setup.
If you want to focus more on casting Hex, Power break etc faster a +4 WIT -5 INT with blessed shots will get you a long way, but do know that you will need empower to make up for the -5 INT.
One more quick question (not good with tats so forgive me if I'm being a total noob).
Can't remember what tats I can get from the shop but if I can buy a +2 STR -2 CON and +3 STR -3 CON would they stack to make up the +5 STR -5 CON suggested?
I'm thinking that as I only need that setup (I'm going Tallum and Kesh Kesh) it would be easier than messing about after Mammon.