IIRC, both have the same truck centers.
Body kits are available for an F59PH from Kaslo in Canada (Canadian and US versions), which show up on eBay and usually stocked in some of the bigger Canadian hobby shops for about $75. The kits were designed for the original Athearn F59PHI, and I'm unsure how well they would work with the new sound versions. The Kaslo kit has some of the coolest details anywhere - and there's loads of it! I have their Metrolink version, but haven't yet started. Very nice stuff.
Cheers!
Marc - Riverside