Question Is the GTX 1650 the best I can get for my SFF build?

You mean 1650, right?

Measure the space for the PCIe slot between HDD cage and back. I think it´s about 185mm, but better check it yourself, so it will fit in the case for sure. The Zotac will need 160mm.

The Zotac comes with a low profile bracket included in the box. You will have to replace the preinstalled bracket with the low profile one.