Mr. Moore may be a excellent engineer, or a good con artist...
His site looks so much like the old catalogues from Luftmeister and CC in California... The pistons do look very smart. Keihan carbs - quite interesting. I will study his site later - my curiosity have been awakened
What is your budget?
How much may the conversion set you back (cost)?
=> gives us an idea of what to suggest, recommend and advice about.
If you want to play it as safe as possible, I would recommend that you get a set of 8.2:1 BMW original pistons with squissband (those perform just a little bit better than those without, in my opinion).
Perhaps you will have to buy pistons for steel-lined barrels and pistonrings for the nicasil barrels that your model have; that's how I had to solve high-compression on the 800-system. Works nicely - no problem.
Currently I am running 1000cc replacement Siebenrock pistons - love them.
But (!) - that is 9.5:1 and as I pointed out above; I would recommend that you do not choose the high-compression solution.
The Siebenrock pistons are about 50gr lighter than my Velonlia 10.5:1 pistons. The Venolia pistons are about 70gr lighter than stock (if I recall correctly) - and runns very smoothly once warm; far nicer than the heavy lumpy unbalanced original pistons.
If you go with 8.2:1 original pistons - balance them (!) and the conrods => the engine runns far better if you do.
Should you want high-compression - study carefully what Alibaba and Mr.MR writes!
My personal experience with high-compression is; good power, good mileage, a ... lot of garage time and heachache figuring out what broke and why. Since I ride in an area where high-octane petrol is available I want the high-compression; but should I ride in areas with questionable petrol, well... I would study closely how the Egyptian Police set up their special R80's!!!
Remeber - as compression raises... so does engine heat... The mileage differens is not -that- great that I would sacrifice/risk durability...
Good - to excellent engine/oil cooling should be your focus as well as looking at the most optimal solutions for keeping the engine running.
The hall-sensor pick-up (ITU) is a source of concern. The braker-point canister used on the late 70:ties models may be an option to consider. Braker points take little room, a spare hallsensor-canister is kind of bulky and difficult to mend on the road. I read here on H.U. about a year ago about this tip on the braker-point option - if I recall correctly VW 1200 (beetle) braker-points fits. You need to check that though - I might remeber it in-correctly.
If you want more power... you could install a turbo or super charger...
Seriosly - keep everything as light as possible and as close to stock as possible, or rather "retro-convert" to more simple and easy solutions for best road-side repairability.
Apply KISS strategy; "keep it simple stupid" - That will save you from a lot of trouble and headache