Scott, I used a farby Drell grinder on my bayonet and rifle. Just make sure you don't grind off the serial number of the rifle and don't grind too much into the metal.
As far as blanket roll or knapsack, you need a blanket anyway so buy that first then later buy a knapsack. Advantage of the blanket roll is it carries easier. The knapsack is better in that you can carry more things in it.
For info on how to make a blanket roll go to our Sykes Regulars link. On the left side of the page is navigation to "School of Instructions" and click that. There is a nice article on that page on "The Blanket Roll." This will show a great way to use the blanket roll. Used this at Bellemead last weekend and it worked great!
Make sure you buy a good quality blanket as it will PAY OFF in spades in cold weather! May have to pay more but you will be pleased later!