Since we're all constructed differently, what works for me may not work for you. To me, the stock 1800C bars are absolutely the most uncomfortable thing I've ever had to endure, but some folks like 'em. So I'll suggest this:
Sit on your bike and see where you want your hands in relation to where your current bars place them. Then figure out the width, height, and pullback you need. Go to one of the catalogs (Flanders makes a lot of bars) and match the numbers.