But if you get the Acard you get the benefit of SCSI with the benefit of CF-card in the same package, a bit expensive yes

Also, loud fans in A2000, A3000 and A4000 are easely solved with modern fans, dont go for a slow speed 500 rpm fan but a standard "quiet" fan. My A3000 is so quiet I can barely hear it

A 2.5" IDE hard drive is actually not a bad idea either, they are typically silent. If they make noice you can always put them in an empty 5.25 CD-rom shell packed with noice insulating mat, 2.5" drives are so cool runing you wont need to bother with ventilation around them.