One thing to note is that the RCN is already planning to build the _Polyphemus_ class of brigade transports for carrying large numbers of RCMC troops around to do nasty things in the Wilds. Thus, while a combat support ship can mean a number of things, doing a _Tarawa_ style troop transport would probably be less useful since they've already got one.
That still leaves a lot of possibilities open, though... Personally, I'd be good with either contest, and it'd probably inspire me to haul out the old FF&S again.
Cheers,
-JTD