RE: powder FPS ?
I can't hit those exact combinations for you, but I checked my Mustang records and found these which should give you a pretty fair comparison.
The 300 grain XTP over 90 grains T7 FFG in a crush rib sabot gave me 1653 fps (5 shot average).
The 300 grain Gold Dot over 120 grains GOEX FFFg in a crush rib sabot gave me 1641 fps (5 shot average).