for whload use, get a desktop a1200, + a 4x IDE adapter and put on that a 4+GB 2.5" HDD (forget cf), 3.1 roms, an accelerator with a full 030 (meaning it has a working MMU) and 8+ MB fastmem, a ps2 mouse converter to use an optical mouse, a cd32 pad to have 4 buttons, a pcmcia network adapter to transfer with amiga explorer the files to your a1200, and finally a scandoubler/flickerfixer to use a normal monitor... that would be a killer whdload 1200, anything above would be good but not that crucial...
The only thing you could use a towered system for whdload would be to have a zorroII gfx card, that would make os3.9 usage way faster and more cool with 16bit+ colors... one that has a built-in sd/ff <-> rtg auto-swith , like the picassoII, piccoloSD64...
