The standard primers are probably okay. Magnum primers are usually used on ball powder for reliable ignition, but that is a debated issue. BTW, W748 is a good substitute for H335, both of which are ball powders.
As far as not being able to find a load for your exact bullet/primer/case combination, I wouldn't worry excessively about that right now, unless you are going straight to max loads ... in which case ... 'been nice knowin' ya! THE MOST important thing is to get the powder charge-to-bullet weight correct.
I would try small quantities of reloads and start off single firing them to make sure they chamber, then go to twosies to make sure your AR cycles, meaning watch for extraction problems.
There is a lot of advice about where to start a load on the "min-to-max" load line. Why not just start at the middle, or maybe just below middle and work up. You will learn a lot loading in small batches. It's supposed to be fun, after all.
I keep one dummy round for each chambering for which I load. If I shoot the same cartridge in different rifles, I have a dummy for each. If I shoot different bullets in the same rifle, I have a dummy for each. That helps for adjusting the sizing dies for that cartridge-chamber combination.
BTW, you did order a small base sizing die didn't you? You need to do that for auto loaders. As far as a crimp goes, you'll have to experiment.
You are on your way. Have (safe) fun.
[This message has been edited by sensop (edited April 09, 2000).]