I would recommend going to the Genius Bar at an Apple Store and ask them if they know of any issues with a dual SSD setup with Mountain Lion. As you do have Lion working maybe you'll need to stick with that until Mavericks comes out.
I would make sure the EFI is up to date in any case: [http://support.apple.com/kb/HT1237|EFI & SMC firmware updates for Intel-based Macs].
I would recommend going to the Genius Bar at an Apple Store and ask them if they know of any issues with a dual SSD setup with Mountain Lion. As you do have Lion working maybe you'll need to stick with that until Mavericks comes out.
I would make sure the EFI is up to date in any case: [http://support.apple.com/kb/HT1237|EFI & SMC firmware updates for Intel-based Macs].
Please let up know what you find out.