I believe that yes, SGC does grade Topps Supers and I don't think it costs any more than a regular card.
According to
SGC's website, they define oversized cards as over 3.5" by 5.5" and I believe Topps Supers measure just under that at 3 1/8" by 5 1/4".
Below are a couple of examples from ebay:
1970 Topps Super Clemente
https://www.ebay.com/itm/32555056017...Bk9SR6LdmKKfYw