I'm going on the assumption that a game that requires 1MB chipram won't WHDLoad on a system with less than that, but now that I think about it I'm not 100% sure WHDLoad can't use some of your fastram for that. I'd assume no, but I'm sure there's an expert around who could confirm either way.
KS2.0 or higher is also required for WHDLoad, so that's one more step you'd have to take on the A1000 to even try it, though it doesn't seem too tough to do.
I always seemed to have the best luck with WHDLoad on 2MB chipram machines, whether an A500+ or an A1200/A3000/A4000. 68000 isn't ideal for some WHDLoad stuff either, '010 is the minimum if you'd like to be able to quit your current game without rebooting, and certain WHDLoad games I've tried used utilities that seemed to require an '020, never looked too far into that one though. Stuffing an '030 accelerator in one of my 500's took care of some of those issues.
