I’m sorry that your thread had been taken off on a tangent. I would say forget the clamcleat aspect of the kicker and just go with the cascade system as illustrated by Ton on the Canadian site – it’s simple, powerful, efficient and cost-effective. 5mm dyneema would be plenty strong enough and is comfortable on the hands.
Outhaul – go with John’s system including extra purchase inside the boom with shockcord. Depending on what sort of fitting you have or can obtain at the outboard end of the boom you may already have a sheave in place, or be able to add one. Personally I wouldn’t bother trying to twin the outhaul back to the helm.
Mainsheet – select a sheet of the smallest diameter that you are comfortable holding; around 8mm is a reasonable compromise, but you may prefer as much as 10mm. Then buy the best blocks you can reasonably afford, to suit the chosen rope. The boom block will need to be a single plus becket (assuming a 3:1 sheet), and for the transom one I would use a fiddle block. Make sure that you buy enough rope for the mainsheet – better to have a metre too much than too little. You ought to be able to sit up near the shrouds and still hold the sheet even with the boom pushed right out.