13" wheels are really the default standard for all small Datsuns these days.

As Boofhead said, just buy some Stanza, 1600 or 180B wheels with tyres [thats t-y-r-e-s] & bolt them on your car. Use the wheel nuts from the donor car if you can round them up as they are made from a larger section material & offer a bigger 'seat' in the rim, but if not, then don't lose sleep over it.

If you keep the tyre size reasonably small [standard size] then you should have no problems.