Taking out a storage device is an option. I'd suggest keeping the SSD if you do; that'll avoid the hassle of migrating or reinstalling the OS should you add an HDD later. Reducing drive sizes is also possible. Removing the HDD and replacing the SSD with a 120GB model save about the same amount of money. Going with a 1TB HDD rather than 2TB nets another ~$15. My best suggestion, however, is a 240GB/1TB combo.
Do I need the cable mod kit or is it useless?
100% optional. It's entirely cosmetic.
Ok. Sorry for asking so many questions. This is my first time getting a gaming PC and I have no idea what I'm doing. Is it worth it for 88$ to get windows 10 and if I don't get it what will the computer have to start off with
No apology necessary. You'll definitely want to get Windows, preferably full version on USB. There will be no software or operating system pre-installed.
Are you saying that if I buy it with windows 10 it will come on a flash drive?