You're in luck. Many of the SV650 owners who have come before you have already tested every type of jetting/pipe/intake configuration there is for that bike (especially Jack Roe, who ran 50-odd dyno runs trying all types of configs).
You should rejet the bike even if you only install a slip-on because the bike comes very lean from the factory, and a freer-flowing exhaust would only exacerbate the problem.
As a baseline, if you get a Two-bros exhaust, and perform the snorkelectomy, you will use this setup for your carbs:
2 shims under the needle
3 turns on the fuel/air mixture screw
Results may vary depending on your altitude/exhaust... but there are a bunch of people on the SV650 list (svrider.com) that have a Two-Bros full exhaust that have found a happy setting.
As far as difficulty goes, if you have someone show you how to do it the first time it's a breeze.