Question about which wheels/tire sizes will fit the econo

Im looking to buy a set of wheels /tires for the econo....I understand that the 14" options are getting somewhat limited...Ive got a set of 14" wheels on the Magic Bus right now that look pretty good filling out the fender wells

Does anybody know what size 15" wheels and tires will fit in the fender wells without spring mods or rubbing clearance issues? . If I buy a set I would like to make sure and get the right backspacing.

A link for a tire calculator to convert the 205/70 14 to a same size 15" tire? ...Or one that will fit that doesnt rub?

Thanks Guys..

if ya have 14's that you like already then try Mickey Thompson tire they still make a decent amount of 14's