This board has raised circuits close by 2 sides of the chip housing (or whatever it's called?) and therefore no standard round heatsink/fans are workable.
Where can I find such a heatsink?
No, there are no circuits that are inside the keep-outs for the cooling solution. You can use any socket-compliant cooling solution, including the standard heatsink-fan unit that ships with boxed processors.
Do you really think that Intel, the company who designed these sockets and wrote the socket specifications, would produce a board product that did not comply with these specifications? Absurd! Not a chance. If you have a cooling solution that interferes with any circuits, then this cooling solution is not compliant with the socket specification and should not be used.