Which of these accelerator's would I be better off getting?

[amigakit]

Another advantage of using real Kickstart 3.1 ROMs is to use NSDPatch et al to allow the use of larger than 4GB hard disks on your A1200

BTW: If your A1200 doesn't have a CDROM, any original AmigaOS 3.5 CD or AmigaOS 3.9 CD bought from www.amigakit.com can be installed onto another medium when bought at the same time such as a PCMCIA to CF adapter or 2.5" hard disk.