Wordpress custom script

We are developing a wordpress site for a railway company.

The company have an Excel spreadsheet that has numerous stations with columns of data that is imported (250+ stations) straight onto the wesite. This is already set up and working. The import creates an individual page for each station, these pages are child pages of one parent page.

We need the following:
1. A MULTIPLE SELECT box which gets populated with all the individual stations child pages, where the customer can select as many stations as they want to compare.
2. If possible once they select the pages then all the selected ones are opened up on ONE SINGLE PAGE, ie one below the other in a sort of compare.

The reason the data is imported is because they are always updating the spreadsheet and once imported it automatically updates all the data and removes redundant stations etc.

Danny