FWIW ...
If you can wait, I think you may want to check the fit of the LX crankset on your current BB and compare how it fits on your bike to ensure that a 122.5mm spindle isn't too long ...
[INDENT]And also, to see if you will need a BB with a symmetrical-or-asymmetrical spindle.
ALSO, if (by chance) you are only going to use it as a compact Double, then you will probably not want the longer spindle ...
[INDENT]My thought is that if you are going to use the LX crankset as a Triple on a (steel?) Road frame, then you may want a 118mm spindle. The multitude of combinations with square taper BB spindles is THE reason that I suggest you test fit the LX crank on an existing spindle & assess ... and then, buy accordingly.
FYI. While NOT exactly the same, I found that I could use a Shimano 6503 (Octalink Triple) with a 112.5mm XTR spindle instead of the 118mm spindle which Shimano spec'd for the crankset on a steel frame Road bike; so, a shorter spindle can be OK.
I did find that the particular Shimano 6503 crank needed the 118mm spindle when used with the aluminum frame Touring bike that I had.
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As far as the OTHER crankset, as you already know, it has a micro-compact spider ... fairly non-standard in its day (I'm going to say that the 4-arm 104BCD cranks quickly superseded the micro-compact cranks for people who wanted the smaller chainrings which were popular on MTBs); and so, even more of an oddity now.
Why not choose a crank similar to the one you will soon be receiving for your brother's bike, too?
You may want to look for something like this Suntour crankset in Oz:
[CENTER]http://www.ebay.com.au/itm/Suntour-Powering-XCE-Crankset-48-38-28-175mm-/322256068846?hash=item4b07f560ee:g:qAcAAOSwRgJXiEZd[/CENTER]