Rolf,
I intend to use sailcut for the design and loft the sail out by hand. Alternative is to ask Sailrite to design and cut one for me. Maybe a better idea to go pre-cut with a radial cut, thanks for that tip!
Or.. I could upgrade to pentex or something and stick with ye olde cross-cut... Easier to fit under the machine...

I have imported a sewing machine from Taiwan, but the machine is unsuitable in its current setup. I can't recommend it due to the crappy electrical system (it is a total joke on my prototype). I have sent the factory details of what is required to meet EU standards and they say they are willing to make the changes and do what it takes to go to full compliance. I'm eagerly awaiting their modifications! If they get it right I will sell them in the EU, but only if everything is 100% A-OK. I'm not looking for trouble, just want to help out other sailors who have small pockets like me.

If you have the money why not get the sailrite LSZ-1. My unit comes close mechanically, but it still needs to be tuned to reach its full potential. I haven't got around to giving it a full tune-up yet. The walking foot is impressive as it is though. I scrounged some Tenara which didn't work well on the industrial Adler at a shop near by, it stitched just fine on my machine out of the box! Also tried some M20 thread and worked fine. I still need to tweak the hook timing to go through more than seven layers of Sunbrella though. It is early days yet and I have only used the machine on test patches and a small sunbrella pouch for my daughter... The real test will be my new trampoline this winter. I think the biggest differences between my machine and the sailrite are the tweaking they do to every unit. Mine still needs that work done. And I sure hope their electrical system is better. I think they are very honest with what they write on their website regarding the differences between the machines. You'd have to check out their patent info to get the details though.