I'm starting a dresser project too, so I've just been through the same thought process. Blum 563 slides can be bottom mounted, so I decided to go with web frames, and bottom mount the slides. My design is different than yours, so my conclusion is different.
My design is a 9 inset drawer double dresser, with wide ends for turned columns at the corners. I didn't want to use the rear mounting brackets for the slides that attach to the inside of the back.
That meant I would have needed to pack out the inside of the frame and panel ends for the slides. In addition, I needed something in the center, between the two columns of drawers, to hold the inner sets of slides. By the time you get all those stretchers in place, it's the same amount of wood as doing web frames, since you essentially need a front face frame, a rear face frame, and the stretchers for the slides.
I drew up both options in sketch up and decided web frames would be better in my situation.
With the web frames, I can attach them to the frame and panel ends with sliding dovetails, so they it will self-square, and help prevent racking.
Your design looks like a great candidate for side mounting the slides to the carcass.
Good luck with your project!