drupal commerce conditional checkout panes
It's surely too late for your project... Anyway, you may use Commerce Rules Extra,  it adds the exact features you need :


  
  Rules conditions : Total product of type quantity comparison : Total
  of products of specified type and with a specified quantity
  Rules actions : Change pane properties : Change visibility, page,
  weight of a pane
  


Once you installed it, in checkout settings , set your pane as disabled by default and create a new rule


event: Process checkout pane
conditions: Total product of type quantity comparison 

Parameter: Order: [commerce_order] 
Product Type: YOUR PRODUCT TYPE
Operator: >, Quantity: 0

action : Change pane properties

Parameter: Id of pane to change: YOUR PANE
Enabled: true
move to : checkout