Most of the kits have a bottling bucket and then you do want to mix your priming sugar in that with the beer. Some kits will have you bottle right from the fermenter and those you need to prime each bottle.
You could buy a bottling bucket. Shipping isn't real slow and it won't hurt your beer to wait that much longer either, in fact it might make it better. It's harder to get the same carbonation in each bottle when you add sugar to each bottle. You need a very good measure to do it.
As it has been suggested, siphon your beer to another container and add the prime sugar there. You will get a better balance of sugar between the bottles. And as a bonus, you will have even less sediments in your final beer.