Pretty big in what way?
AT32UC3A0512 - 32-bit Flash Microcontroller based on AVR32 UC core featuring 512K bytes Flash, 64 KBytes SRAM, 10/100 Ethernet MAC, full-speed (12 Mbps) USB 2.0 with On-The-Go (OTG) capability.
The AT32UC3A0512 also feature SRAM/SDRAM external bus interface.
The AT32UC3A devices deliver 80 Dhrystone MIPS (DMIPS) at 66 MHz and consume only 40 mA at 3.3V.
All in a LQFP144 - 20x20 mm package (same as that xilinx breakout board I already have) - 109 - 5v tolerant i/o pins
Actually the AVR32 would make the basis of a very nice co-processor card - the ram interface card could be the first option for it.
Well it's an option