Just to put the cat among the pigeons (err...so to speak)...my first choice for SL would be Verbatim 16x +R (MCC004) - seriously, who thought I wouldn't say that?
OK, the MIC ones might not be up to par, but MII and both flavours of MIT have been great for me. And yes, I use them for archiving as well as everyday use.
Although the 8x TY SL has been regarded for a long time as the best in the TY range (and I would agree), I've read mixed stuff about the actual JVC branded ones. No harm in giving them a shot though, your drive(s) may really like them.