I did this hack and it worked out fine.
I made an aluminium bracket to mount the 2.5 harddisk on.
I put the cdrom on the leftside off the amiga1200.
I also had to add an extra powerplug for the cdrom for reliability reasons.
I am also using an AT psu to power it.
Maybe because it also has a blizzard 030 and an internal FF inside which pulls too many amps out off the psu.
picture is here:
http://romeo.messageboard.nl/8931/album_pic.php?pic_id=20I also mounted an delfina clockport soundcard but couldn't get it to work properly.
But maybe a subway will still fit there??
Ooh I also tried the CF cardtrick for the harddisk but that wouldn't work with the cdrom.