Open Ticket Numbers in a Custom Single Dropdown Field

[Louie Goode]

I have an idea I would like to implement. I would like to create a way in which external service techs would check-in and out with a timestamp while onsite. In order to do this, I was thinking about creating a portal and having the tech select the existing Ticket number from a drop-down list of Open tickets to and enter timestamps.  Once I captured that I can either add the times to the existing ticket comments or create a sub-ticket. 

My only issue is how do I get a list of open tickets to display in a single select drop down? (I am open to other suggestions I have not thought of as well.)