[sassan]

And surely you have at least two of EX580 or are they in wish list too?
IMO a body from two digits D (i.e. 20,30,40,50) or 5D plus 28-70 f2.8 L and an EX580 II (or if budget is tight, EX550) are all that any Canophilic photographer needs to complete his art of showing the best pictures to others and especially covering a wedding or likewise.

A 300 f4 IS is absolutely not needed for portrait unless you are talking of some sort of candid shooting. Well for birding etc, Please do yourself a favor and don't settle for anything less than a 100-400L even thought this L has the nasty fame of being a dirt sucker! If too serious and then with fat wallet, then you may want to consider 300 L 2.8 plus a TC 2x.