16 is better that 8. I am able to compare my two desktops. One with 8 and one with 16. 240GB SSD drive in each one.
This will be impossible to find for windows 7 but an SSD hard drive also speeds things up. Dell might make it for you. A current i3 processor is good enough. No need for i5.
I was looking at i7 processor and 2T hard drive - and the 16GB. Is that overkill? I’m retired and don’t do gaming or any extreme processing. Watch Netflix at times.