You can get that same functonality, Ports 0-3, plus Ports 4-7 where ports 4-7 can be configured as an external data bus. You can have it work in multiplex mode, non-mux mode, 8 bits of address or 16 bits address modes. And you can use all the bits like normal Port bits. This is a ready made part as opposed to a soft design that needs to be put into an FPGA. Look at the Cygnal C8051F020 or C8051F126 in the TQFP100 packages.
Michael Karas