You want to add an IDE controller hooked to the ROM header? Not possible, sorry.
But there is some hacks that allow installing a pair flash memory chips (not Compact Flash! : flash RAM chips) using a little adaptor board, then programming the chips outside the Amiga.
With new flash "ROM" hooked in the Amiga you'll have the ability to reprogram it as you wish.
Look for ROM flash on Aminet.
