Recommend an LSI 9211 for 6Gbps. Get either a 4i or an 8i. It will have multi-lane connectors on them.
" 'With the first link, the chain is forged. The first speech censured, the first thought forbidden, the first freedom denied, chains us all irrevocably.' Those words were uttered by Judge Aaron Satie as wisdom and warning... The first time any man's freedom is trodden on, we’re all damaged." - Jean-Luc Picard, quoting Judge Aaron Satie, Star Trek: TNG episode "The Drumhead" - Alex Smith