Pivoting toe plates or other similar non-sliding rudder controls are worth making or buying if you have the money. The Sealline set-up is pricey, Prijon makes a simple pivoting footbrace for about $30 less but I think the use of adjustable webbing (I think that's what it uses for the adjustments) for the connection to the rudder cable is messy with too much slop/stretch to it.
1/8" vectran is amazing and with a constrictor splice and strong bungie pulling the toe plate under tension works surprisingly well for adjusting cable length. I don't know if it will fit in the cable housing or if the narrower 7/64" stuff adjusts as easily by hand as the 1/8" vectran does with a loose constrictor splice but it's a thought. I used the stuff to adjust between the cable and toe plate within the cockpit. It looks sloppy but works fine, like a chinese finger toy, push the splice together and the line slides through, under tension it holds like a crimped cable loop. It would be worth attempting having the line travel all the way to the rudder just to avoid those sharp ss wires. Nope, checked 1/8" looks too big for the black housing. Maybe the 1/16" spectra stuff with a teeny jam cleat would work but I'd worry about it coming loose under hard use.

http://www.apsltd.com/depts/dept222.asp