I actually have a Protector leather rabbit ear bag for my rear bag. I also have a front bag but find it to short and am tired of always looking for something to raise it up.
BullBags. It supports the whole rifle stock from the trigger guard forward. Filled it with cat litter so it wouldn't be too heavy. It is solid as a rock.
Protektor standard front bag with solid base and Protektor rabbit ear rear bag also with solid base. Like Tracker 12 I found the front bag too low so I made an adjustable front bag holder. Now I would just buy a Lyman Bag Jack as I think they look ideal. Both bags are filled with iron sand.