I have the following build: https://de.pcpartpicker.com/user/fraxture/saved/4cQqqs
Will this card fit into this machine?
Do I need a lager power supply; if so, which one? Are there other mid-level video cards I should consider?
The card will fit, but you definitely need a higher capacity PSU.
Check pricing and availability on Radeon RX 480 graphics cards in your area. If they're less expensive than the GTX 1060, get that instead.
The 1050ti would be an easy pick without changing the PSU though.
The downside is the performance drop.
GTX 1050 Ti