2000 190hp at the crank, about 150hp to the wheels
2013 305hp at the crank, not sure about the hp to the wheels but you can guesstimate.
So yeah youll notice a significant difference. But uhh..question: If youre willing to go out and get a loan right now for a 2013 why not spring the extra for a GT? If the extra is really a concern you could look for a used 2011 or 2012 GT and still have the same 5.0 engine pushing 412 crank HP for possibly the same or less than the '13 v6.
If youre hell bent on a V6 youll have to do some mods to up the power to what I think youre looking for.
Edit: Your current car might need some maintenance to improve how it runs. If you dont know how recently the fuel filter, spark plugs, plug wires, air filter, oil, and oil filter has been changed I suggest doing so. I would clean the MAF sensor as well. That might wake the car up a bit. Thats still a whole lot of miles on the car.