Definitely go for the A1200. Upgrades like an accelerator and fast RAM, which will be necessary for WHDLoad, will be much more readily available and probably cheaper than A600 equivalents. Plus as has already been mentioned, you have the option of AGA games on the A1200.
As for your Workbench, if you have plenty of fast RAM then you can go wild. Birdie for textured borders, VisualPrefs for customised gadgets, nice backdrop, 256 colour NewIcons.
There are various patches on Aminet which can force certain apps to put their images in fast RAM, which will help to conserve valuable chip RAM which you will need for games.
--
moto
