An SSD will breathe more life into your system than you can believe.

"Just to give you some encouragement, I just upgraded my system to split the system and data drives. I went with an SSD for the system and a WD Black for the data. Even though I have an older processor, this system feels very fast now. Sonar loads many times quicker.
 
Good luck!"
Ditto on this.  I have a much older processor.  I am baby stepping my way to a new system and did the same thing. I did a clean install of Windows 7 as well.   Everything has been working well (so far)  I plan on using the new drives with my new mobo/processor.  But for now, It is working.  If I had an i7 I would just stay with that and do as others have suggested.  Unless you have the money to just buy one from Jim Roseberry. Which is what I would do if I could afford to just have one built.  (someday)

I suggest a complete replacement early next year. Motherboards with thunderbolt 3, USB-C will be available and Windows 10 should have fully matured. An off the shelf PC including these specs should work fine (DAW requirements aside), go for 16Gb min RAM though I suggest.