Just wanted some opinions on this singlespeed conversion kit with a godspeed tensioner, shimano dx cog and spacers https://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MEWA:IT
ends up being less than 55 for everything. The cog and spacers are standard issue from what I have seen so I wanted to know if anyone had any opinions on the tensioner.

EDIT: I just noticed it in the mountain bike section. Would this work with a 8speed rear freehub for a road bike? I am not sure what hub is on the bike (need to ask the seller) but it uses shimano sora components and is a cassette in the back.

i used a conversion kit produced by 24seven cycles which was also aimed at mtbs and it worked fine on my sora hub. mine wasnt made up of lots of spacers, only two larger ones, so this kit should be fine as you can really fine tune the chain line.
but in answer to your second question i belive it should sit fine on the freehub.
i do not have any experience with the tensioner though.

That looks like a good deal for a non mechanical person wanting to convert. Good chainline adjustability and no worries on getting the perfect chain tension through sprocket math.
Me, I would drill the cassette rivets to free up a selection of sprockets and 50% of the spacers required. Then I would go to a hardware store and buy 2" of abs plumbing pipe. (Any naysayers, check out what the spacers in a cassette are made of.)
Now I would have 3 front and 8 or 9 rear sprockets to play with. With this I would play with until I had a good gear ratio and perfect tension so I would not need a tensioner.
After I had the chain line and sprocket choice made, I would buy the one bmx sprocket I want.
Sound easy? It is.

that kit is pretty nice looking, its like the one i have on my bike.