Whatever is the cheapest. Any decent 9mm will feed most everything except hollowpoints, and semiwadcutters, but those are expensive anyways.
Cheapest bet is Lead Round Nose reloads from Wolf in kingston Ont. PM me for the web adress if you like. They are $240 shipped, but I am closer than you. Prolly under $300 bucks for 1000 rounds delivered to halifax. They also do FMJ for an extra fee.
Just stick to Round Nose and you will not have issues. Lead is just a bit cheaper, and it is available from commercial companies like PRIVI PATISAN or whatever it's called. Or just go with the Full Metal Jacket if you don't want any cleaning hassle.