I may not have this right, but it sounds like you’re looking for a stand that mounts to the side of your entertainment center. If so, you could use this, leave the wheels off and drill it into the side:
HumanCentric PC Stand – Computer Tower and CPU Stand Cart | Adjustable and Mobile PC Holder with Wheels https://www.amazon.com/dp/B07RGRV1VX/ref=cm_sw_r_cp_api_i_.JAGFbB0CWE6K
I gotten a lot of my stuff from amazon. the Tower stand so my stand wouldnt touch the floor was a been to small for tower. width wise. Theres a lot on amazon. just got to measure the tower and make sure you pc can fit in the stand.
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