I personally prefer maga kissa because they usually have a shower, and it will sett you back about 2000-3000 yen, my recommended place is Raum in kabukicho, because their night pack is the longest one I have seen (10h).
As for karaoke box, I have done it and it`s a good last resort. Karaokekan have a night deal on weekdays thats 1000yen from 12 to 5, and it`s quite comfy, but as it lacs showers I woulden`t stay several nights in one.