Collecting flows at an IXP

Hi All I'm busy doing some digging to find a solution for collecting layer-2 flows data on a medium sized IXP. All we have at the moment is some MRTG graphs and we're trying to get a better view into IPv4 vs IPv6, src and dst MACs, packet sizes and also perhaps port & protocol trends. I found Richard A. Steenbergen's NANOG 39 presentation and not much since then. Is it still correct that Cisco does not support sFlow? Are you able to get the same kind of useful data using Netflow v9? Which FOSS flow collectors do an decent/adequate job at crunching about 10Gbps worth of flows and presenting it in a useful way? Thanks -- Graham Beneke