Whats ways are there to submit a page that hasnt loaded yet?

In Apex 4.2, i have Page 1 that a user makes a number of selections via dropdown lists.

There are several servers they can choose and for each server, there is one multi select that lets them choose a number of applications on that server

E.g. Server 1 - App A, App B   Server 2 - App F, App G

I count the number of applications they have chosen for and store this in a hidden field.

When they click a next button (which is set to Submit page), it takes them to page 2 passing the application counts for each server (defined in the branch section when Next button clicked) and the count fields on page 2 are used to determine conditional display as well as restricting options in other drop down lists.