Maybe I'm missing something... But if you want to have the handlebars high need one of the following:

a) high top tube
b) a ton of spacers under the stem
c) a sloping top tube

What does wheel size have to do with this? Also, why do you care about standover or toe overlap? These things don't matter when you're on the bike riding at more than a few miles an hour. Again, not trying to criticize but just make sure you're getting the best custom frame.