Thank you for the recent reply to my questions, I believe I am starting to understand.

a) Fortis does not come with burner

b) Fortis Plus also does not come with burner

c) Fortis Grande does come with LP burner.

a) I am still considering which unit to buy, for both the Fortis and also Fortis Plus are you able to provide an LP burner as well (same or similar to the one provided with the Grande?  

b) If I proceed to purchase the Fortis (with LP burner) and later decide to upgrade it to Fortis Plus by also purchasing (later) the cyclone and the stand, is this possible?