Yeah, I put the Powertaps on the fixie when I TT on it, but I wouldn't want to do that in traffic. I don't think switching pedal bodies on a regular basis is a great idea, so I'd forget about the fixie and concentrate on bikes you will be "training" on. I suspect that it's quite hard to really screw up well made pedals or turbos, which is why I got secondhand pedals, and a secondhand smart turbo.
Given the choice between double sided pedals or single sided and a smart turbo, I'd probably do the latter, just because there's not much you can do with the L/R numbers, even if you do collect them, while the smart turbo makes things nicer every time you get on the thing.
FWIW, while I have L/R pedals, and I can see the balance on my headunit, I do my ride analysis on Trainer Road, and they don't bother with anything to do with L/R. Unless you have a significant imbalance, I doubt there is a huge amount you can learn/action with it.