What is the front end to your solaris application? Does it also reside in Solaris or does it reside in Windows? In Web? etc.... The front end location is a greater determinant of how to generate load than is the backend.
It depends on what your application is doing. For most business applications I worked with the only difference is how you will monitor the server - scripts are the same (some differences can be for the WinSocket protocol). Is a native graphical front-end only way to access your application?