You should have your shoulders measured (takes most of 60 seconds) and then get the appropriate bars for yourself. Your local bike shop should be able to help you with this.

Brifters can be moved/slid up or down a little bit, and you can rotate the bars a little in either direction, which gives you a lot of "play." There isn't one right answer, though. Photos of you on the bike would help.

Your hands are going numb because you have too much weight on them. Wider handlebars won't fix this, although they should be cheap, and if you need them, you should still get them. Probably a different stem is the first thing to look at, then saddle angle ( is it level with the road, now? ), then fore/aft.