Polar meter with tripple cranks?

Hello,

Short version:
- Does the polar power meter work with tripple crank-set (theory / practice)?
- What is difference from PT pro to PT SL - other than 160g weight?

Long version:
I consider a power meter - currently just for fun, but maybe I will in 1-2 years consider competing again. Question is what are the options to consider. I have (regretting) triple crankset (specifically cervelo soloist team with FSA tripple).

1) Polar power meter: does it work with tripple crank-set?
Price is around $700, varied opinions on reliability

2) PowerTap pro: Apart from 160g heavier than SL and 2.4, are there other differences? Is the more/less reliable than the SL and wireless? I am fairly light (64kg) - does the pro hub exist with fewer than 32 spokes? How much is saved in weight and aero with fewer spokes?
Price $900+wheel

3) PowerTap 2.4: wireless is nice. But, is the cadence sensor also wireless?
Price $1600 with Mavic open pro

Currently, I have Easton Cirquit wheels. If I go with PowerTap, what would be a good choice:
a) mount PT hub on my existing rear wheel
b) Mavic open pro rear, keep easton front
c) New wheelset with PT.

a) and b) are same price - which is the better wheel: mavic open pro or easton cirquit?

c) could be zipp 303 or 404 - how much better is that than my current wheels? would I be able to feel the difference? I may start some triathlon - would the zipp wheels be a big advantage for that?

Thanks
Henrik