When I had my ACE 750, I replaced both front & rear (I'd worn them both down to horibble hooked points). I got mine from "Sprocket Specialties" or "Sprocket Specialists" - I can't remember the exact name. There are plenty of folks here who've "been there, done that, got the grease under the fingernails to prove it." You can find them on the web & they have a multitude of sprockets made from different materials & even colors.
For me, it was a pretty easy swap. I did also replace the wheel bearings while I was in there. But, it was easy because I took off sprockets & replaced them with sprockets. I don't have any idea what it'll take for you to replace pulleys with sprockets.
I went with the stock 17 on the front, but shaved down the rear from the stock 41 to a 37. It was a pleasurably notable difference on the highway & only a little bit different from a dead start with my wife on the back.
You're actually raising the ratio, meaning that your bike is going to work even harder than it already does. Stock is 41:17=2.411, 40:16=2.5, 37:17=2.176. So, you're going to lower your gas mileage. But, you'll have a little better torque coming off a dead stop. Sounds good if that's what you want.
