Powered is cheaper but best thing to do I have found is to pit some TV in a pint glass and add the sweetener bit by bit to your taste then scale it up for your batch. Adding super will cause it to ferment again but that's ok if you want to carbonate it.
I made some turbo cider about 3 weeks ago and it was just not clearing, so moved it outside as the temp has been hanging around 6-8 and it cleared over night. So a lower temp will help out alot i covered to keep sunlight off it tho. :cheers: