I do like your odds, although the site says it’s currently unavailable.
Sorry haven’t responded quickly but work has been taking up most of my waking hours lately. Anyway yes the fans need to be 24V and yes the hotend fan is a regular fan and the part fan is a turbo fan but both are 24V. P.S. the noctua fans are not that much quieter and as you saw you would need a buck converter because they don’t have 24 v versions.