To get you to AWESOME and give you a computer that's much faster for your purposes, the main ingredient will be the USB 3.0 ports and upgrading your external enclosures to USB 3.0. This alone will make your transfer speeds likely at least 3 times faster than what you have now.
If you are currently connected to the internet through a cable/DSL modem or router, the only thing that will speed up your d/l's is a faster internet connection(or more people seeding your d/l ). The 10/100/1000 LAN is just the interface in your computer that the ethernet cable from your router/modem plugs into to allow your computer to communicate with it on your Local Area Network. If you find you need wireless at a later date for a new e-reader, laptop, etc., you can simply get a wireless router.
You need win 64 bit to make use of your 8 GB of memory.
You do not need any of the upgrades you mentioned, but you do need to upgrade to an SSD boot drive in addition to your 1TB hard drive. There is no other upgrade that can even come close in taking that computer all the way to !AWESOME!