What country ccTLD is .sc? I think the ext spoils the names, but I'm not familiar with .sc I guess some take it as standing for "source", but the big TLD's are still .com, .net, .info, .org and .de. Try to stick to those if at all possible, and of course good keywords in .co.uk, .co.jp, china if you know what you're doing, and maybe the other big European countries like .es and .fr, and in the new world, probably .us in the future.
Sorry I can't appraise these I haven't really looked into .sc at all.
One good way to find out is a cc tld is worth regging is to find out if there have been any significant sales in the past. Has there, for .sc? There have, for sure, for co.uk, .de, .us