My recommendation would be to let other factors dictate your decision, such as battery size/range. If you're good with the standard range battery (since the Pro is only available to retail customers with the SR battery for the time being), just buy heated seat covers aftermarket. If you need the extended range battery, then you're looking at at least a very expensive XLT, which might have optional heated seats anyway.
But here's the real kicker: have you considered ventilated seats? Heated seats are nice, but once you have a car with ventilated seats, it's really hard to go back to regular seats.
