Best Dell Precision Workstation for gaming?

Hello,

I am looking to put together a cheap gaming rig - and it seems getting a used workstation and upgrading it is the cheapest way to do so. 

I already own a GTX 1660 Super so the PC would have to be able to handle that.

I've previously owned a T3500, which was good for a few years, but failed recently soon after installing the 1660 super. 

The T5500 looks good as it has a bigger PSU so reduced risk of frying it with the GPU. Are there any other similar options? I've heard a lot about optiplex but the smaller form factor is off-putting since my GPU is a triple-fan.

Any input is greatly appreciated!