I think that either V69 or V92 would be OK with Clipper Canvas 7.2oz, but V69 is probably thick enough. So long as the needle is an appropriate size (about 21, I think), your machine should cope with V92.

I suggest you turn in the edge twice, so that there are three thicknesses, and to cover the raw edge; but also add a wide doubler (to add weight and stiffness) that has its outer edge under the turned tabling. I don't think you need rope; webbing would be necessary if you don't add all those layers of cloth, but not otherwise. Sailmakers don't put webbing inside tablings when using cloth intended for sailmaking (do they?). If you need more layers for eyelets, add patches at the batten ends. I've never used triple stitching. The black dabond thread has a long life and retains its strength, and if two lines of stitching are liable to be chafed, so will the third.

Doesn't Peregrine look wonderful with her black hull?  And the Chinese rig doesn't look at all out of place among those classic gaffers, either.

The Tyvek source I found was incredibly cheap, compared with woven cloth. That wasn't the issue, which was that I wasn't at all impressed with Tyvek as a sailmaking material, unless for a disposable, experimental sail.

I have some sailcloth on order. "EnglishSeadog", on Ebay, has the remains of the stock of Hayward's Clipper Canvas, and I've bought plenty of tan-coloured 7.2oz/sq yd, 170 cm wide, at £5.89 sq m.  That's much less expensive than it used to be when Kayospruce were carrying the stock, and it's excellent cloth, with a soft feel, which is good for a cruising junk rig.

All well, then.
I admit that I tend to pile on as much sail as possible, as long as I can hoist and sheet it. When rigging Johanna, back in 2002, I probably touched my limits: To hoist her 48sqm sail, I had to use the winch for the last two panels. Later I fitted an electric winch handle (which I have kept). After first having sailed her for two summers with the BR, I knew her rudder was very powerful, so I gambled and gave her 5.8m long battens (Chord=5.71m), which meant that the sail’s chord was 84% the length of the waterline. Johanna still behaved quite well, and could carry the same sail area, or one panel more, downwind, compared to when close-hauled.

Recently, when I designed the rig for my IF, Ingeborg, my hearth wanted a 40sqm sail, but my head vetoed against it, so I landed on 35sqm. The idea is to be able to hoist sail without needing a halyard winch. With the battens being 4.9m, the chord/wll=80%, so I hope Ingeborg will steer well enough, downwind.

When I spotted David’s sailplan for Weaverbird, I noticed that she appeared to have a very good rudder, and that was my reason for thinking she could carry more sail without needing a longer mast. I guess my attitude is... there is no substitute for square-meters, downwind... and I am too one-eyed to think that other people may see it differently...

Anyway, good luck with your project, David!

Arne.