Brake upgrade questions

No, you can't just add larger front rotors. That will throw off the front to rear brake bias. If you go Giro, you need both front and rear rotors at the same.

If you are getting into DEs, I would strongly suggest the brake upgrade. What is the most important part of your car when you are going 100+ mph into a 40 mph corner. Stock parts are ok, but I would put my first money into brake upgrades to stay even safer. They work better, run cooler, fade much less, last longer, and are less likely to fail or have a problem due to their higher capacity to stop the car.

Caliper bolts definitely add convenience for pad changes and also safety by reducing the wear on the aluminum upright that they bolt into. Not sure how taking out the old ones will affect that aluminum upright. I would just call Ira at Target Engineering and explain your situation. He might be able to recommend a stud length that could work for your stock calipers and one that could also work for the larger Giro Disc rotors and their spacers. The difference will be 10mm more for the Giro setup. I just ordered 85 mm studs for my PCCB calipers.

AP911,
Physically, you can indeed put Girodiscs on front and keep the stock in back. BUT, ... Girodiscs for the 981 are designed to be used with and include spacers to hold the calipers further (10mm?) away from the hub than stock. That changes the leverage of the caliper and therefore increases its stopping power. Imagine that you want to torque a bolt with a short wrench vs long wrench. Applying the same pressure (which is what the 981 will do) to the longer wrench will put more torque into the bolt than with the short wrench. So it's not the rotors that change the bias, it's the spacers. And you can't use these rotors without the spacers since the stock calipers will not fit over them otherwise. If you put Girodiscs on the front, you'll need to put them on the rear as well to keep the same brake bias. That said, you can certainly take your chances with an altered bias.
B

Well I have giant OEM GT3 Pads on my 350 mm Giro disc with 6 piston PCCB calipers and they are worn out after only about 12 days. These pads have over 50% more surface area than stock and still wear out in less than a year. So everyone does not have the same demands placed on their brakes depending on which tracks you visit and how you drive. The difference between beginner, novice, intermediate, advanced, and instructor level driving places varying loads on a car's braking systems.

Fluid, pads, and a different duct are a good start and may work for some, but not for everyone.

That is a good start initially, but as your driving level advances you may want to add per say a Giro Disc upgrade to larger rotors to increase your heat tolerance and resistance to fade. These rotors go from 330 to 350 in front and 298 to 325 in the rear. Many have complained about the rears getting too hot from an over anxious PSM and this upgrade helps alleviate that problem as well as not getting premature "brownbos".

The next step can be what I did with the OEM PCCB calipers and thicker 350 mm discs all around. This is basically a factory option from Porsche for the 981, but with steel instead of carbon rotors. In his well massaged Cayman S, JCviggens is running within a mile or two per hour of the top speed of the GT4s at his track, and Porsche sees fit to put 380 mm rotors on that car. So if you are running a modified Cayman with almost 370 hp and are an advanced driver, then brakes with 350 mm rotors is about safety and longevity of the equipment and not bling.

For reference, when a pad is 60% worn, I consider it as done when going to the track. You need that last 40% of the pad as insulation from heat to protect the pistons from passing the heat into the brake fluid, boiling it, and causing fade or worse consequences.

Everyone is entitled to there own opinions, and these are just mine. Maybe they are worth two cents or maybe they help keep someone from having a brake failure some day. I recently read about a GT3 guy on Rennlist that had a major off when he had a catastrophic brake failure due to a caliper bolt coming out of the front left upright. The caliper ripped off and destroying that whole corner. Consequently he only had brakes on the front right and left rear to stop the car. He is thankful to still be here today. I now have caliper studs on my car like all the Cup cars do. Maybe that is overkill, but I don't want to be the next guy telling a story about his close call with almost meeting his maker.