Hey mate...
I'm not that familiar with the powertap chai rings so won't comment on them... But,
I replaced the bottom bracket on my 2009 trek Equinox a while back and I'm guessing it would be the same.
I used a shimano ultegra bottom bracket, English thread and it went in no problems and the shiimano crank should go in with no problems.
The bottom brackets are so light that there prob won't be much difference in weight... But if your current one has been used for quite a while it is prob worth installing a new one... Especially if there is any lateral play in the chainset.
Goodluck

Thanks for the info! I think I'm all set to pick up the upgrade.

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Madison photographer Timothy Hughes | Instagram