For Sims 2 - do I want an i5, i7, or i9 chip?

I seriously need a new computer - to replace my Win 7 Dell desktop. It is having all sorts of problems. They are all different, but go something like this:
I get a critical error on boot.
Boot in safemode, read the report, research the problem, do the 'fix'.
Then it boots normally and works fine for 2 - 3 days (with absolutely no errors.)
...Then *sigh* we do the whole dance over again with a different issue/error code.

So... I'm starting my research on what to buy.
- I think I remember reading that the chip makes a difference for playing TS2. Do I want an i5, i7, or i9 chip?
- I know I want as much RAM as possible - what is the highest amount that can be put in a new computer these days? My Dell is maxed out at 8gbs.
- I want a NEW machine *sigh* so I will have to go with Win 10 (I hate W10 on sooooo many levels, but I can't get an UNused PC with W7 can I?) - W10 is iffy for TS2, I know. But many have absolutely no problems with it. I think, if I get the right equipment/machine, it should be OK.
- I already have a nice 750watt PSU that works fine. I have a new GPU (the GPX 1050 ti with 4gbs extra RAM.) And I have a new 1tb HDD - I'm thinking all those can transfer to whatever new machine I buy. Right?

I am just starting to search. I really don't know what I'm doing, but I'm pretty good at researching/sussing things out.
I've got time, but not a lot of money. So I need to make the best choice I can. Any advice or reference material you can point me towards will be welcome Thanks!