Did you consider adding some SPI RAM chips for swapping? I think that would be the bomb.
Did you find out anything from periferal hardware, how it can be addressed without using SDK (and which we didn't already know
![Wink ;)](./images/smilies/icon_e_wink.gif)
Do you know how to change the CPU speed to above 160 Mhz? I did find some hints here and there but nowhere it's described exactly how to do it (i.e. where the PLL registers are and how to program them).