Are you also going to play pc games on that? If you're only planning on using Dolphin, that build would be really overkill. But yes, it will indeed run Dolphin really well, especially if you OC the processor.
Also, regarding the build, you should maybe go for a beefier PSU if you are planning on OC'ing. The 550W should be fine for that machine at stock, but a 600W or 650W would be preferrable if you decide on pushing the CPU and GPU. On the other hand, if you do NOT overclock, that liquid cooler is really not necessary and you should instead go for a cheaper air cooler.
Also, regarding the build, you should maybe go for a beefier PSU if you are planning on OC'ing. The 550W should be fine for that machine at stock, but a 600W or 650W would be preferrable if you decide on pushing the CPU and GPU. On the other hand, if you do NOT overclock, that liquid cooler is really not necessary and you should instead go for a cheaper air cooler.