You're fixing to have some fun and some frustration (but hopefully not too much frustration)
It's not stupid to start out small, and once you find a good load, you can stock up. Half the fun of reloading is experimenting, though! Generally, you can substitute components, as long as the specs are the same (i.e. the bullets weights are the same). For just blasting ammo, the brand doesn't usually matter. However, some bullets vary dimensionally between brands, so you will need to adjust the OAL to work in your firearm. Don't just assume the OAL in the manual will work. (are you using an AR-15?) A good starting load for H335 with a 55g bullet (FMJ or SP) is 24g of powder with a maximum of 26g. OAL again depends on your firearm. 1 lb of powder will give you about 300 rds. of .223 by the way, so that matched the number of bullets you got. Cool!
For H335 powder, you need to use a magnum primer for reliable ignition, but I don't know if the Fed. 205s are magnum or not. Personally, I like H322 and Varget powders.
Go ahead and load dummies, but you don't strictly need to. A headspace gauge really helps with the sizing die setting. If you do load dummies, I would suggest you don't crimp the cases until everything else is right if you want to recover the components, as a crimp makes it really hard to pull the bullet (you DO have a bullet puller don't you?) I don't need one, since I never make mistakes
I would use one case to get the case sizing right, then get the powder charge right, seat the bullet to good OAL, etc. taking one station at a time, that way you don't have to use up so many cases, but remember you have to actually shoot some to see if they feed in your gun (unless it's a bolt gun).
I don't know about cheap polishing media, sorry. It's not too bad even at gun shops. It lasts a while.
Hope you get your stuff soon and have fun! Email if you have any other questions.
<chuckle> Wating to start is like waiting for Christmas all over again, isn't it?
P.S. You'll need a case trimmer also, before long, since the cases "stretch" a little after firing. Reloading for pistol's a lot easier!
[This message has been edited by Gopher a 45 (edited April 09, 2000).]