Hello all, I just picked up a 2015 GSXR 600 and I’m wanting to add a full exhaust. The bike is currently bone stock with low miles. I’m wanting a Two Brothers full system but was curious as to whether I should get the whole system or if I should just keep the stock headers on, get a mid pipe(cat delete) and a slip on. Are factory headers as good as aftermarket headers? And I’m assuming I should get an ECU flash before having the exhaust installed? Thanks in advance for any help given.