Personally, I don't like nitrous. Too many opportunities for loud, unpleasant noises followed by total silence.
The problem with giggle gas on an inline is the poor design of the stock intake manifolds. There's no way that a plate system is going to feed 1 and 6 at the same rate it feeds 3-4. This may or may not be a problem at 50 HP but it will be at higher levels.
Which engine are you looking at? On a carbed 300, a plate system should work with an Offy or Cliffy manifold. On an EFI engine, a spray bar could be put between the upper and lower manifolds. On a low revving 300, nitrous is going to create much more internal loading than on a normal engine, so you may want to reduce your shot size accordingly.
On the small 6, you ight be better off trying to fit a 6 nozzle fogger.