hyper v – Core i7 vs Xeon in a different scenario

I googled to know the difference between i7 and Xeon processors mostly both processors are compared with gaming perspective.

I want to run Hyper-V and Android Stuido for simulations, I’m going to buy a used PC under $400 budget, please help me what are the most important things i should keep in mind.

And also in this scenario is it helpful to use dual processor or its better to use one but newer?
is it better to install ram in smaller modules like instead of 16gbx2 should I install 8gbx4 modules?
In such scenario what is the importance of # of Cores, # of threads and Cache size (like 6mb Cache etc.) ?