Says a guy in a car 500lbs lighter and 6 inches lower, from the factory

 

sure you're right, just go fast and worry about stopping later.

 

He wasn't asking about braking, he was asking about suspension.
Yes high-temp fluid and better pads are required for the track.

 

a sway bar still has been the best improvement in handling full stop - yeah, the coilovers helped, but before and after rear sway bar was chalk and cheese

brakes are obviously an important upgrade, that's why im running a bbk, better rubber helps the braking anyway - our stock tyres were junk to begin with.

 

My list based on my experiences:

#1- Tires. If you don't have good tires, the rest is useless. Depending on what kind of motorsports you plan on doing, treadwear may be an important consideration. Some classes have limitations on how low you can. Star Specs are popular for a reason but the RS3s are certainly gaining ground. Good luck finding them though as last I heard, there is a 3 month wait.
#2- If you plan on tracking the car, and this means doing more than 5 laps at a time, replace the brake pads. Despite what some may tell you, you don't need a big brake kit; it won't reduce stopping distance. Buy pads that can handle the heat and you're golden. Replace the fluid as well with something that can handle the heat.
#3- If you're only doing the odd track day, I would just go for sway bars and call it a day. Coilovers in Canada are a *****. You either have to swap out the suspension twice a year to account for the seasons, which means two alignments a year, or you deal with ****ed up threads that mean you can't raise or lower the car. Coilovers also change the way the ride feels. Sway bars don't, they're inactive unless you're taking a corner.

That would be my recommendation and it's more or less the route I went with my cars. As said by cfdfireman, seat time is the most important factor. It's very easy to get into the mindset that you need mods to get to the track but that's a load of BS. I know guys who track on winter tires and are faster during their show laps than guys with R-comps and all kinds of big buck mods. Why? They know how to drive. You don't get to be a good driver by buying your way to the top. A good driver can make a slow car fast, any idiot can make a fast car fast.