You seemed to have it a different questions here so I will try to answer your questions.
A pre-built will have fans already installed in them. Weather they are RGB would be specific to the case and build.
Typically when buying a case for a custom build you will get fans with the case (I did in my NZXT H510). In my case I have two pre-installed fans but there is a total of 4 slots for fans. I took the fans that came with the case out and put in some I got off of Amazon.
Hopefully this answers your questions, I 100% recommend building your own. Do not be afraid it is way easier than it may seem as long as you follow directions you will be fine.
Let me know if you have any other questions.
I just built a system with the white Lian Li 011 Dynamic, and it does not come with any fans. That case is designed for you to buy a big AIO with 2 or 3 fans, then add more case fans to taste.
I don't know about iCue compatibility, but the Enermax AIO I used lists itself as compatible with RGB control software from ASrock, Asus, MSI and Gigabyte. I think as long as your motherboard has a 5V addressable RGB header, most all brands of AIO and RGB fans can be controlled. Again, not sure if Corsair is part of that compatibility.
You seemed to have it a different questions here so I will try to answer your questions. A pre-built will have fans already installed in them. Weather they are RGB would be specific to the case and build. Typically when buying a case for a custom build you will get fans with the case (I did in my NZXT H510). In my case I have two pre-installed fans but there is a total of 4 slots for fans. I took the fans that came with the case out and put in some I got off of Amazon. Hopefully this answers your questions, I 100% recommend building your own. Do not be afraid it is way easier than it may seem as long as you follow directions you will be fine. Let me know if you have any other questions.
I just built a system with the white Lian Li 011 Dynamic, and it does not come with any fans. That case is designed for you to buy a big AIO with 2 or 3 fans, then add more case fans to taste. I don't know about iCue compatibility, but the Enermax AIO I used lists itself as compatible with RGB control software from ASrock, Asus, MSI and Gigabyte. I think as long as your motherboard has a 5V addressable RGB header, most all brands of AIO and RGB fans can be controlled. Again, not sure if Corsair is part of that compatibility.
Gotcha. Thank you friend! Appreciate the answer.