I can certainly see why the Cards would want Reyes, but it's so hard to see it happening.
I'm not even sure if they could fit his full salary on their payroll right now. I think their situation is pretty tight, but I'm not sure.
I'm certain that Toronto would be sternly rebuked if they asked for either of Miller/Taveras, let alone both of them. The Cards would likely give up Martinez to get Reyes, if they have the payroll space, but Martinez alone probably isn't enough to make it worth it for Toronto. What else could St. Louis add? Maybe they could put Allen Craig in the deal, since 1B isn't big enough for him and Matt Adams, and it would free up a bit of payroll space. But then Toronto has a hole at SS and they're trying to win in the present...
Anyways, it's all moot because Reyes is almost certainly on AA's "untouchable / would not trade" whiteboard magnet list.