Low cost dev kits with SDRAM?

Hi - awhile ago, I had tried to do an audio delay project with Arduino but couldn't manage to create big enough buffer to delay up to 10 seconds with SPI SRAM. The purpose is to sync up AM radio play-by-play with cable TV broadcast of sporting events.

I had put the project on the back burner, and then today I came across two Atmel dev kits which offer 8MB SDRAM for under $30:

AVR XMEGA-A1 Xplained MCU Evaluation KitAVR XMEGA-A1 Xplained MCU Evaluation Kit
AVR UC3-A3 XPLAINED Evaluation KitAVR UC3-A3 XPLAINED Evaluation Kit

I'm curious if any one has experience with either of these kits. I don't think I need the 32-bit power of UC3-A3, and the XMEGA-A1 would likely meet the needs of my project. Although they are both about the same price.

I'd also appreciate if anyone could recommend any other low cost dev kits with offer SDRAM. I don't particularly care about the architecture but would like to be able to program in C.

Thanks,

Drew