I'd like to use qt with NetBeans, where can I download the Qt SDK?
Since NetBeans is just an editor, you must also choose which compiler to use.
There is mingw Qt that comes with compiler OR
visual studio 2015/17 where you must install that yourself from microsoft.
If you are on linux, then gcc is already there.
Make sure to use the Qt compiled with the compiler you want to use.
Qt have some special tools (moc.exe) that needs to be run.
It seems supported
the link takes me to an installer. Would this file install ALL the Qt products, Designer, IDE, compiler (if needed), etc?
You get all of Qt. ( make sure not to install BOTH mingw and
visual studio Qt version unless you really intend to use 2 compilers)
You can choose mingw compiler+debugger which is included OR
choose Qt for visual studio, and in that case you must install the compiler and debugger yourself.