I don't have all the answers I'm afraid but I can give you my experiences with the Kadet slide. I have a SP-01 Shadow that's had some custom work done to it and a Kadet slide that Angus' shop fit for use with it. My Shadow is an absolute pleasure to shoot and perhaps my favorite thing about the Kadet slide is that it uses the exact same grip and trigger that my Shadow has. My friend has a Browning Buckmark that shoots very well but it's just not comfortable for me to shoot - I always try to grip it too high and the safety rubs into my hand. On the contrary, my Shadow is a perfect fit for me and has a wonderful trigger to boot. I will say though that since I lightened the springs up on the Shadow, I've had to stick with Federal for my .22lr ammo. With CCI mini mags, I end up with about 1/10 light strikes. Still, that's not a big problem for me - I could easily fix that by putting heavier springs in it but I prefer the trigger the way it is now and Federal Target shoots just fine. I've put about 600 rounds of Federal .22 through the Kadet in the last month without a single problem.
I will add - they do make some really nice loaders for the Ruckmark and Ruger 22's. If you go the Kadet route, I'd pick up the modified uplula that Den makes.