*No need for a Z270 board with a locked CPU and 2133MHZ Ram - pick up an H270 or B250 board for much less.
*Skylake and KabyLake benefit from dual channel RAM moreso than previous generations. A 2x4GB would be a smarter idea than a single 8GB module.
*A 240GB SSD will fill up fast if it's your only storage device. Make sure you pair it with an HDD.
RektSkrubz :
Pretty good actually, but you can find Windows 10 and 7 OEM liscenses cheap on ebay. I got my last license for $10.
While it's true they are available, I wouldn't recommend picking one up. There's always the potential they're already in use, have been stolen, have been purchased with a stolen credit card etc. Always buy your OS from official retailers or MS directly...