Opinion:
Figure out exactly what you want to do.
450hp end of the day is just a figure. Do you want response, do you want a time attack, rally or circuit car or road car. yada yada
Once you know exactly what you want, go about figuring out what supporting modifications you'll need to get there.
Just remember, it's more fun to drive a slow car fast than a fast car slow...
So remember to do all your suspension, brakes, wheels and tyres FIRST. They're what transform the car (in my opinion remember).
There's been discussions surrounding MCA suspension recently on here and for track one bloke who got a suspension setup from MCA dropped .7 of a second off his PB with no other changes to the car.
Gearbox, just putting it out there and like what Boon said, big power is the death of 5 speeds. Worth time/money investing in a 6 speed.
That's my 10 cents.
P.S. While I agree with Kwi_fozzie about the whole Link thing, if long run you're wanting something for motorsports and something that at the end of the day has a butt-load of power, probably your best bet, just not needed yet. They're not going to go up in price.