First of all, the PSU used is a special one that does not use a conventional 24 pin main connector.
There may be an adapter around that could make a standard ATX psu work.
Possibly you may find that the mounting holes for the motherboard are some sort of a subset of ATX or, you could create new mounts yourself.
Since your objective is to install a better graphics card, I think you could install a low profile GTX1050ti which would be an upgrade.
If such a card is not sufficient, then use the cpu, ram and I/o on a new build using standard parts.