Hey Gtt, you're in my area! I'm from Ajax but am working (or pretending to) in Pickering today! My step-bro used to work in the service dept at Pickering Toyota, which is a good place for service but a horribly bad place to deal with for sales. Whitby is better from what I've heard, or even making a drive to a place like Ken Shaw Lexus Toyota in mid-west-central Toronto. I dealt with Ken Shaw when I worked at Toyota Canada and they were very pleasant, bought a Celica for my mom through them, and they also handle the Automobile Protection Association's (APA's) customers too if I remember correctly.
I happen to like the Epica too - and at a $17,500 cash price vs $25K MSRP, they're a great deal. Unfortunately, I think the seats are more foreign small than what you're looking for and raving about in the Impala. Impala is a value-oriented, larger-if-somewhat-uninspiring car, with a roomy interior and decent power, and plays that role well. An all-new Impala goes into production for '06MY, but that's aways off - and there's nothing wrong with today's model.
I'll have a look at dealer invoice on the '04 and '05 Impala tomorrow to see if I'm off base from what I typed above as I was pretty surprised by the mark-up on a Malibu MAXX (though it's not for everyone, think it's a neat combo of flexible interior room and unique look) when I had a look.