WinUAE with that computer and p96 installed should fly...
What do you normally get 020 at 150Mhz?
Using a seperate HD is preferable... but you have lots of ram so there isn`t really going to be a problem.( winVmem cashe access).
I would down load the latest WinUAE (and still use the Amiga Forever rom...it is the 3.1 rom?)
the settings are quite stable if you don`t use the FPU , or higher than an 020...
JIT set at 4mb is fine.
http://homepage.uibk.ac.at/~c72578/amiga/uae/Worth reinstalling directX again...
BTW ibrowse is what i use.
good luck.