I like the Williams WGRS sight for a peep. Fairly inexpensive and works well. It has more adjustment than the XS system. You will most likely have to change the front sight with the use of any aperture sight. The 444 is definitely a handloading proposition. My 444SS is a later version with ballard rifling. I had Tom at Accurate molds make a mold for me, although the Hornady XTP bullets work well also. My mold drops a 275 grain gas checked bullet and a 285 grain plain based bullet. I shoot mostly mild charges of Red Dot or Unique in mine. Somewhere between 1,000 and 1,200 fps. These loads put a lot of fun in what otherwise could be a brute to handle. My rifle sometimes thinks it's a benchrest rifle.
Best of luck with yours,
Rick