How do I upgrade case?

[Amn3]

Hi everyone, 

I want to upgrade my GPU and PSU, but the fact that I have a SFF case is holding me back a lot. Instead of buying a new pc, I'd like to get a new case and move all my current components to it.  I currently have a HP ProDesk 400 G1 SFF with a HP 18E9 motherboard. If I get rid of my SFF case, and get a bigger case, I can finally buy a better GPU.  I cant find any info about how to change my case, so my questions are the following: 

How do I know which cases are compatible with a HP 18E9?

Do I need to buy anything, or can I literally move everything? 

I heard that my CPU cooler is 'mounted' to my motherboard, not my case. How would I mount it to my new case? 

I'd also appreciate good case recommendations (at like a 100$ budget). Any tips are appreciated, thank you. 

[Prométhée]

hi

seems hard to do
you have a very small computer, so with a very small motherboard, I don't see how it could fit in a "normal" box
the processor being directly on the motherboard, I don't understand what you want to do, the cooling system, is on the processor, not otherwise
but consult the documents, you may understand better how it works

•  HP ProDesk 400 G1 Small Form Factor Business PC Specifications
•  System Board Connections

Maintenance and Service Guide HP ProDesk 400 G1 Microtower HP ProDesk 480 G1 Microtower HP ProDesk 4...

 Illustrated Parts & Service Map HP ProDesk 400 G1 Small Form Factor

[Amn3]

Are there any normal cases supporting my small motherboard? And is that the only thing stopping me from moving all of my components, or is there more I need to know about if I try swapping them? 

[Prométhée]

I strongly doubt it, look at the dimensions of your motherboard, and the standards found in the box
You may also not be able to connect everything
if you want another case, you should change motherboard, you will have better upgrade option

check this @old_geekster  ' KB

Moving HP Motherboard to a new gaming case