http://www.midsouthshooterssupply.com/
https://www.grafs.com/index.php
http://www.midwayarms.com/
powder (BH209)
http://www.powdervalleyinc.com/
other powders
http://www.powderinc.com/
sabots -
http://mmpsabots.com/ or
http://www.harvesterbullets.com/ (Harvesters are cheaper and just as good, sometimes better). You can also find those at some of the dealers linked above.
Yes, a heavier bullet will produce more recoil than a lighter bullet, given the same charge. The difference can be considerable. Be sure to read and follow all guidelines in the rifle's owner's manual. Best not to push the limits.
10mm 200 grain Hornady XTPs in a 50/40 sabot from MMP or Harvester would make a nice projectile and produce light recoil even with heavy charges. Several here use that bullet on deer with excellent results.