I started on a progressive but would initially just run one phase at a time. There's no need to buy a single stage when you can just put one die in the progressive and replicate single stage functionality. I am currently using a LNL and really like it. If you're planning to do 223/5.56, the LNL...
I had a huge pile of brass that I picked up after a rainy period. I threw it in a 5 gallon bucket with some degreaser and water for a day or so to loosen up the mud, then I added about an ounce of lemon juice to a couple of gallons of water for the next step. After a short soak period, maybe 30...
They say the only exact science is math, and my math came up the same. The 100 packs, or by the case is the way to go unless you're loading slugs, buckshot, or other specialty loads. I love the MAOmart term!!
The 200gr is shorter and you're wanting to keep case space similar so you will need to have a shorter OAL. I reload with 200 gr RNFP and have to go down to 1.17 to keep them from hitting the lands. Maybe compare a 230 and a 200, see what the length difference is and adjust OAL by that amount.