Kevin: People will have different opinions on the 357 mag regarding 200 meter ram knockdown. I have one, and am still experimenting with loads. My last match, I hit 6 rams, and rang all 6, so as you can see, i've not found the magic load yet. I hear Greta Graves, the gal who won the ladies silo championship at Raton last year used a 357 for the 200 meter match. I'm not sure what her load was.
I have a Rossi 1892 that limits me to jacketed bullets. Will shoot cast bullets out to 50 yds, but with longer distances, accuracy disappears. I've been experimenting with the old Nosler 180gr Silhouette bullet with 13.5 gr of H110, which rung the rams. I either need to use a heavier bullet or up my powder charge above and beyond published recommendations. The only jacketed 200 gr bullet out there is the Speer, which would be way over length for my Rossi, unless I used shortened brass.
If you are really in the market for one rifle to shoot 2 matches, I think the 44 mag would be the one. With me, I already have the 357, and I don't see another rifle in the near future for me.