Well, the 1050 Ti is the fastest card that you can use without needing to spend more money on a new power supply. It's a simple upgrade, remove the old card and install the new one.
If you plan to buy a power supply then you should make sure you pick a power supply which has the connectors the videocard needs. If you decide to get a 1060, you'd want to make sure your new power supply has the connector that specific card requires.
You have not listed a budget, how much do you intend to spend? What resolution? The different models, one fan/two fan/mini/low profile, are all the same in performance for the most part. The choices are more personal and based on your needs. Some people want more fans, some people need a low profile card, etc. As long as you have the space for a regular card, you can pick the one you want.
edit: That is an older motherboard, Sandy Bridge generation. I'd suggest you do some looking around online, to see if the newer Nvidia cards have trouble on computers such as that. AMD might be more compatible, an RX 470 for example.