Hi Stevil2k!
The limit on what hard drive you can use in the A1200 is dependant on the version of the OS you're using. If it's bog-standard with Kickstart 3.0 the limit is 4.3GB, if it's Kickstart 3.1 nad OS 3.9 it's, well, big enough for you. Don't know what the limit is but I've got a 120GB drive on mine and it's working no problem. If you wanted, you can use a different filesystem though and this will solve the problem to a certain extent. SFS is free, but you'll need to be reasonably competent with HDToolbox etc. In all cases anyway you'll have to keep your system partition entirely below the 2GB mark, as the OS needs to use this to load the updated versions of (or patches to) scsi.device you'll need...