I'd say order from Ken as well if it's your first time. He can at least show you some pointers on how to use it and help you with your pad selection to make the most of your 7424.
If you're already experienced or know exactly what you want, you can try
Coastal Tool. I bought mine from there years ago and they seem to have pretty much the lowest price on the Internet. ($119USD with free shipping) You'll need a US address though to order from them (and possibly a US credit card if you can't enter in a Canadian billing address) They also have a selection of Lake County pads and backing plates if you don't already have some.