It has been discussed before, and using both stainless for the studs and nuts isn't considered foolproof, as "galling" is a known problem whereby the two can fuse together, just like steel studs/nuts rust together. There again if you never want to take them out again, no problem. Personally I replaced with steel studs and stainless nuts, which aren't quite as thick as the oem ones, leaving quite a lot of thread exposed. Using dome nuts and copperslip solved that problem, as they are easily removed once a year to check all's ok and reapply copperslip.