OK, I'm home now. But anyways, the reason I like Socket 1155/1150 and not new hardware, is because new hardware IMHO is overkill. You don't need a Ryzen/Core i9, to run the most demanding games. Last generation hardware runs great and is still compatible with Windows 7. As for why I prefer Windows 7x64 over Windows 10, that has more to do with customizing start up and shut down screen then anything. Windows 10 is perfectly fine as well, but not as customizable. Another thing I like about 7 over 10, is you can turn off Windows update. This is important if you want your PC on your wired/wireless network for remote administration (I use TeamViewer to do my cabs remotely). Remote administration is nice because you can leave out admin buttons like "TAB" if you like and or are worried about others changing the configuration on you purposely or accidentally. It also enables you to sit back in your nice cozy office/gaming chair and use the keyboard/mouse much easier. The reason I say go with an x64 version of Windows 7 mainly has to do with architecture changes in mame over the years. I believe the only version they put out now is x64 based and if you want 32 bit you need to compile your own, or use an older version. Though I might be wrong about that, perhaps someone else can chime in there. Also, on a 32bit system, you are limited to only 4 gigs of ram. While this is probably enough, I like to go 8 gigs mainly because I'm a Hyperspin junky and it ensures smooth operation. Recommended hardware would be like a socket 1155 with at minimum a Core-i3 3220. That's a nice cool running 55 watt CPU that should be able to keep up with most whatever you toss at it in mame. Personally, I'd go Core-i5 3570, or even Core-i7 3770 if it's within budget. GPU I'd say go with a GT-1030. Myself personally, I use a passive cooled ASUS GT-1030 2gig. The nice thing about that GPU, is I never have to worry about the fan wearing down and it's dead silent. Cooling on the CPU, I prefer using a ARCTIC Alpine 12 CO
https://www.amazon.com/gp/product/B07HJ3DNX2 the CO stands for Continuous Operation. I've used them since my crypto mining days where I had machines going in the garage 24/7. For an arcade cab... pure awesome.