mine are minilites 14 x 6 / with 185 / 60 tyres, works ok and looks good

all depends on the offset rod, as a 14x6 with a +10 is a much different thing to a 14x6 with a +24....

the info 'toomanybelletts' posted ages ago is spot on correct. he's the tyre/wheel shop owner i mentioned earlier, and has been around bellett's for longer than me (ive got 22 years under my belt now), and has tried countless wheel and tyre combo's, so i'd believe what he says (due to real life experience) before a few words on a website....

It might have seemed like pulling teeth, but I wanted to get this figured out before buying wheels on the other side of the world, paying more than the purchase price for shipping, pay to have them painted, then pay to have tires mounted and balanced, and finally discover the tires cutting against the fenders or frame, or worse yet, the wheel itself hitting something.

The conflicting information from different sources is annoying.
And some of the cryptic responses were "Every Bellett has different wheel fit requirements". (Thank you cryptic person for not providing even the faintest hint of an answer).

I looked at toomanybellett's answer, and also at a Japanese response which may be the same guy from the Watanabe website gallery picture (14x6.5 +16).
I ran those through one of the more idiot proof wheel and tire size calculators I found:
http://www.rimsntires.com/rt_specs.jsp

The size I want to use is 14x6, with a desired tire size of 195-60-14. These are the sizes that came on the Piazza, and have been my desired sizes for street tires for even my later Isuzu cars which did not come with those sizes. The tire protects the rim, they ride and wear decent, and the additional tread width adds a little more grip without much more friction. The diameter might be a fraction bigger, but I'll just let it slide. (I am seeing a 5 speed transmission and 4:11 rear end in the equation anyway...).

My choices for offset are +16 and +21. I type the wheel size, tire size, and offset into the size calculator and compare to the suggestions, and for the most part, what I want to use has close to the same or slightly more clearance than some of the more extreme suggestions.
And the size calculator kicked out the back spacing numbers, which explained some of the numbers that toomanybelletts had provided.

I'm going to try out a pair of cheap, used +21 wheels. If I don't have them refinished, I won't be risking as much loss if they are completely wrong, and the worst case I can see is I might need 5 mm spacers if the tires rub against the frame.