In my honest opinion, adding a motor to a vintage/antique bike, is hacking. Especially doing this to such a good bike ! Many Schwinns are highly desrireable !! $$$ You said that you also wanted to customize it, too. The wear & tear of a HT bike motor to any bike is damaging. " EASY Bolt-on kits ?" If you think that is what the HT kits are,, you need to read more. If you absolutely must put a motor on it, I suggest what " Terrence " said, above. A rear friction drive kit would be a better && easier installation choice & it can be reverted back to original. Read a little here, & get more info about your bike.
http://www.schwinnbike.com/usa/eng/forums/index.php
http://www.schwinnbike.com/usa/eng/forums/index.php