Suitable Graphics card

The strongest graphics card will be determined by the power supply you have, or are willing to install.
In a typical pre built machine, you may see a 300w psu that has no 6 pin aux power connector.
The strongest card such a psu can run will be a GTX1050ti that is not heavily overclocked and does not need aux power.

If your pc is a small form factor, then you may be limited tp low profile cards.