Its going to depend on how competitive you want to get, and what class you want to run in.  In a stock class you are likely going to be better off in car with a factory performance package.

If you're going to modify the car anyway I'd save my money on the premium those cars command and get a more stripped down model.  Frankly all the electronic gizmos cars have now confound me, and I can live mostly without them anyway.  All it does is add weight, and when handling is a priority its always going to be easier to get a lighter car to handle than a heavier one. 

Now in AutoX skill means a lot more than what car you drive.  I've tooled a lot of guys in cars that are better than mine on paper over the years just because I can drive.  What really matters is how well you know the car and the degree to which the car inspires a confidence in you to find and push the limit.  To be blunt, on a short course a V8 American muscle car isn't going to do that well because it sucks in transition.  A light, nimble AWD Japanees car like a WRX or an EVO rules those tracks.  On longer courses where straightaway speed matters you have an edge provided you have decent brakes and don't totally flub the corners.