2700 is extremely high for first pc build... If you where experienced I'd recommend a all in one water cooler for everything A 9900k or a thread reaper depending on what you need the pc more 32-64 gb of ram 800-1000 watt psu with good power grading 4 tb ssd Propably whatever rgb you want A good motherboard depending on what cpu you choose... A big case with a side window to fit your all in one water cooler and have plenty of space About windows 10 you could buy them but you don't need to do so... There are virtually no disadvantages on downloading downloading the installer and pressing I don't have a key for your version and installing it