The cranks aren't weak. They are better than all the aftermarkets. Most builders use the stock crank to stroke it. Anyway, what type of riding is your wife doing? That is going to dictate the cam you use. With GOOD p&p work and a mild cam, you COULD see 7-9hp. These bikes need more comp, only 9.2:1 stock, go with a 10.25 or 10.5:1. That has a great feel to it, and can run pump gas. You can go as much as .080" over bore, 366cc, but the cylinder is at it's limits, and gets thin. Honestly, most of us prefer the .040" pistons. Still have 2 more over bores left that way. Using the Vito's key will help the bottom end come on faster and stronger, too.
Several of us have the stage 1 hotcam and like it. Myself and Weston have em, and '00 WO YA! does as well. None of us have any complaints. It is very close to the Web .390, but you can use the stock valve springs and rockers with the hotcam. You need HD springs and hardweld rockers with any of the 3 or 4 Web cams. Megacycle makes 2 cams for these bikes, the 252x1 and 252x2. Both require HD springs, but no hardweld rockers, so about $130 cheaper right off the get. Stay away from the 252x1. Nothing wrong with it, but unless all she does is run WOT all the time, it is going to be too top end happy for the stock stroke. That's why I'm using it in my stroker. Several of us have the 252x2, and seem to like it's power. It gives a stronger mid range, I believe. Never ran the stage 2 hotcam, but it is deisgned to be used in their +4 stroker kits, to bring the top end back into the power band. It's not a crazy big cam like the 252x1, so depending on riding style, mods, and gearing/tire size, it would prob perform ok.