So here's how I rigged my brake cable so far. I say so far because I'm not too happy with how well it's working. I ground off the stops on the calipers like Calfj60 suggested, and it made a big improvement in pedal travle for setting the brake, but my own design has limitations that I didn't quite think through.
I'm able to set the brake completely at about 8-9 clicks up on the handle (factory spec for the drum ebrake), but when I release the ebrake, the caliper with the stronger spring (right side in this case) pulls the cable and keeps pressure against left's mechanism, causing those pads to still press against the rotors quite a bit. My original intention was that using the snatch block would allow for uneven pad wear and put equal tension on the calipers when set. I'm sure it does, but due to the uneven way it's releasing, I'm probably putting way more wear than I should be on the left side pads. I'm going to do some more research and figure out a better way to rig the cables that'll allow for easy adjustment and firm, solid setting of the brakes. I'm kind of dissapointed that this method didn't work out, because it sure came out looking clean and almost professional.
Another problem I have is the way I routed the Eldo cables. I'll be running them along the axle when I redo it, so that I can avoid having the cables anywhere near the exhaust, like so:
