For kickstart there is Relokick which I used quite often with the 1200 as it allows you to soft kick into 1.3 and made a huge difference in game compatibility.
I used the "most recent" 1.4a
, but to be honest I never had much luck with it. If a game was giving me issues, the Relokick never solved it for me.
Ever since dropping to the 2000 (I say dropping because it's on WB/KS 1.3, which is a very different world than 2.0+) I've not had a single game issue. That being said, I almost exclusively play games that were made pre-1992...