Both rims are fine. The 27s are a little wider... which is nice. If you use heavier spokes (2.0/1.7-1.8mm) on the DS rear (at least), then 24f and 28r should be ok.
Your body weighs over 86,000 grams... so keep this in mind while sweating 40g on your wheels.
Your body weighs over 86,000 grams... so keep this in mind while sweating 40g on your wheels.