I have to agree with Bloodwych as his ClassicWB setup is much more useable than 3.5 or 3.9, in my opinion anyway
I too have a Blizzard 030 and used a utility called Blizzmagic from Aminet which loads a 3.1 rom into memory. I put it into C: directory along with the 3.1 rom and added a line in startup something like C:blizzmagic kick.rom (the name I gave the 3.1 rom) and it worked everytime. Then using my WB3.5 CD I installed WB 3.1 then upped it to 3.5 then 3.9 (had to edit startup a few times to put the C:blizzmagic line back in). But I went back to the ClassicWB setup because it does everything I need then more. As they say oop North "if it ain't broke why fix it"
I would probably only upgrade to WB4.0 (when it comes out) if I had the machine to go with it.
Probably not the answer you are looking for but if you want to spend some more cash on your Miggy get a decent monitor, more ram, bigger hard drive or something. It'll love you for it