Hey thought I might be some help, since I,m also Canadian and have been to ibiza 4 times. First off don't be swayed by the big parties with the over priced covers, some of the cheaper nights are sometimes less crowded(u actually have room to dance) and might have better music. Second I personally think your going at the wrong time(July and August r way to crowded)out of the 4 yeaars i've been there the last week in June, first week of July and by far the first 2 weeks in September are the best. As clubbing goes if your more into house: Mon-Roger S@Pacha, Tues-Underwater@Pacha, Wed-Sublimminal@ Pacha, Thur-Cream@Amnesia(which is more trance but @least u won't spend your whole vacation @ Pacha, Fri and Sat are god days to rest and do some Sight seeing, Sun-Space, and go to manumission once Mondays@Privilege it's very over priced and not as good as it used to be but check it out, if u can hook up with some people and get a VIP table in the balcony it's much better as it's way to croweded, however VIP tables run about $2000 Canadian. If you r more into Trance/Thecno: Mon Cocoon@Amnesia, Tues-Gatecrasher@Amnesia, Wed-Good rest day or check out Pacha(it's house but u gtg atleast once) Thur-Cream@Amnesia, Fri-Slinky@Privilege(a new night might might be good), Sat another good rest day and Sun-Space. Also my personal favorite is Extravaganza with Alex Gold it used to be Fridays @Privilege but is moving to another night or another club(hopefully) it's definetly the best mix of house and Trance. Also make sure you go to the Circo loco parties monday mornigs @DC10, I would get there in the early afternoon though, as the police sometimes wait in the parking lot in the mornig and search you and your car. Also as others have said see the sunset in San An, I personally like cafe mambo because after the sunset some top name DJ's usualy come down and spin for half an hour or so. Hope this helps.
PS Are the raves in Montreal still as good as they used to be, last one i went to was Cream about 3 years ago.