whats best GPU should i get with i3 CPU - Ethereum Miners

Assuming your GTX 1050TI has a hashrate of 14.2 MH/s (average I found online), you could net a whopping sixteen cents a day, and that's not accounting for energy costs.
Here is a table representing what you would be earning with that card/hashrate:



As you can see, you will actually be losing money (if you pay for the electric bill) by mining Ethereum with this card.
You will not start making a solid profit until you get upwards of 175 MH/s. 175MH/s would be over ten of that particular GPU.

Cryptocurrency mining is not nearly as lucrative as it once was. It's incredibly difficult to turn a profit with it unless you have a great deal of funds at your disposal to build/buy an incredibly powerful mining rig. The only way you'll make money without doing this is by finding a coin with a lower difficulty level and waiting for the value to rise. Please bear in mind that mining can be incredibly harmful to your hardware and will shorten its lifespan. Be careful with what you're doing.