Ambrosio rims with wire beed contis come to mind. You might want to also try the following which has worked for me:

-mount as much of the tire as possible
-deflate as much as possible as was suggested
-when you get to that last bit that's hard to get on even with tire levers do this next step directly opposite
- pinch the tire with both thumbs and draw them along the sidewall in opposite directions (contrary motion for all you piano players) in an effort to stretch the tire in hopes of creating more slack
- try the lever again
*others have used soapy water OR talcum powder (but then your wheels smell like a baby's bum)