View Mode for new page

Hello everyone, I have a bookable unit type called 'condo'. When I fill out the availability form and show rooms on a per room basis, I have them styled to a teaser format. By default, unit types only come with 1 display mode. I can create a new view mode with Display Suite, but it seems booking/start_date/end_date only uses the Default view mode. Here's the workflow :

Search for condos which returns a list of condos, each with 'Book this room', showing in the default view mode it comes with. This is at booking/start_date/end_date.
I have a custom title field linking to a separate page using tokens. This passes a unit ID to bookthis/%id/%start_date/%end_date which shows the same format, except it shows only the one unit, not a list of them. I would like to have this show a different style or view mode.

I see the ROOMS_INDIVIDUAL constant and I think that might have something to do with it. I can use hook_theme to make my new page use a separate template file, but getting it to display with a different view mode is where I need the help. I just have to be able to 'Book this room' from the actual room page. Maybe I'm going about this all wrong?

Any help would be greatly appreciated!