I already have something similar, Marcus. I bought the same type of blades that fit in my hacksaw. I used them to cut the damaged ends off of a multi-colored slate whetstone and ended up with two slurry stones in the process. It worked well for cross cutting one fairly soft stone as I could cut without the need for water.
I want to both crosscut and rip cut lengthwise and I want to do it to 3 or 4 12ks. As much as I need the upper body workout ;), This little project is a job for a precision machine that will do the work in short order and with little effort. If I had a ton of disposable income, I'd buy my own stone saw for like $400, but I couldn't justify such a purchase, so a $45 rental is fine with me. It'll be fun and worth the money just to do it.
My only hope is that after I'm done cutting up the 12ks that I don't grab my 8"x3" natural coticule combo and rip that lengthwise. Shame on me that I'm tempted to do such a crazy thing, but I really like narrower hones at this stage.
Chris L