Making a classic Amiga run on a x86 processor is not only very diffecult but also not logical.
And why stay with the old machines where parts are getting hard to get a hold on ?
Sure my Amiga's are still pretty fast both have a power pc and a fast gfx card,lot's of memory,disk space,zorro and pci expansions etc..... but if you would make an x86 accelerator you still be stuck with some big bottlenecks.
Compared to the vast majority of the pc's it is still a lot faster in getting the job done but when it comes down to raw CPU power,bus&memory speed then i notice the age of my machine's.
In my opinion PPC is atm the only logical way to go for the Amiga and thus preserving the technology that makes the Amiga uniqe.