The 550 is an outstanding reloader. There are dealers in Canada (P&D, CRAFM etc) . The machine will load anything (except .50bmg

) and is reliable as hell! If there are issues with it, I have reloaded ~100K rounds on mine since purchsed, Dillon has the best absolutely NO BS warranty in the business. You will have your parts in a week which is pretty damn good from the US!!
Also if you have any concerns or technical questions they are VERY knowledgable (which seems to be hard to find in a lot of places these days).
I do not use the strong mount.. I cut a piece of 3/8 plate, painted it Dillon blue and bolted it to the bench and then the machine to it. Looks great and works awsome. Any similar mounting system will work well . You can even bolt it directly to the bench as long as it is sturdy enough. ( I built my bench to my specs and used three pieces of 3/4 plywood laminated together for the top.)
The strong mount, in my opinion, lets you tailor your mount to your height need: if you laready have a low bench it will raise the machine to a height that may be more suitable to you. The same is true if you have a higher bench but you are tall and prefer to load standing up. The few accessories that bolt to it can easily be situated around your set-up. I find I like to tailor to my needs rather than adjust to some one else's designs but that's just me
I would definately get the roller handle... the standard round handle works loose as it does not rotate in your hand as you use the press. I would also, as others have, recommend lots of primer tubes (in both sizes) and tool heads for each caliber... that way the change over takes all of 5 minutes or less.
Hope this helps.
Regards,