Owning a car that actually stops when you want it to is great, but maintaining a performance setup gets expensive fast. Between pads, rotors, and labor, the bills add up every few years just to keep the car safe and fun to drive. If you watch the calendar, parts usually dip in price around major holiday weekends like Memorial Day or Black Friday.
You should deal with the price of the kit and the cost of installation as two separate conversations. Get a few quotes from local shops before you buy the parts online, and ask if they will install customer-supplied components. A financing window is handy for spreading out the hit, but you want the hardware locked down at the right price first.
Remember that the 0% for 18 months on purchases and balance transfers from date of account opening is a strict deadline, not free money. If you still have a balance left when that window closes, you will get hit with interest on the original amount from day one, so make sure your monthly payments actually cover the whole kit before time runs out.