Only Laserfiche 9.1 has been certified to work on Windows 8.1

But unofficially there's no reason why it shouldn't work with 9.0 as windows 8 is on the supported list.

Being a Surface Pro has no bearing on the client - it's still running windows and has full x86 compatibility and Laserfiche is still a windows x86 based program.

However a Surface RT will not run. RT requires the program to be a Metro based program and the client is not. However I suspect Web Access will work just fine outside of the the office integration/snapshot features.