Best utility bike wheel size?

A few weeks ago I snared a nexus 7 speed hub on ebay. Now I'm wondering
what wheel / bike to build it up into. I'm thinking of a round the
shops utility bike for the family in general in the flat middle
south-eastern suburbs of Melbourne

Options are for it to go:

As a 700c into an upgraded 70's Raleigh Ladies bike used by my better
half - I have already brazed cantilever bosses onto this one and
upgraded the fork. currently running a 7 speed deralier system

As a 26" into a older MTB frame all I have is the fram and lots of
bits

As a 451x18mm into one of my Raleigh 20s I have a folder and a rigid
one. I have two frames and one set of wheels steel rims on a 3 speed
Sturmey Archer

All thoughts would be appreciated

RoryW


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Rory Williams

As a 451x18mm into one of my Raleigh 20s I have a folder and a rigid
one. I have two frames and one set of wheels steel rims on a 3 speed
Sturmey Archer


If it was me, I would build the 26" as a commuter.

If you decide to build the 20" and are looking for good alloy wheels
etc, I have a foldie with a bent front end that has nearly all its
parts available.

Craig.