There's a TSB for motor mount replacement. I've done all three of mine, after my PSMM utterly failed, and my transmission mount nearly so. The rear motor mount really wasn't in any better shape. Luckily, changing them is a piece of cake, and during an oil change is a great time to do the job, because you already have the car in the air, and the bottom cover off anyway! Most of your work is done!
For the PSMM, I went with a $40 one from RockAuto. It's lasted me about 60,000 so far, and no complaints.
For the rear, I went with a 70 durometer AWR. It added a bit of NVH (noise, vibration, and harshness) to the ride, but it really firmed up my 2-3 shifts in my manual car. It's been on there for 5 years now, and other than the increased NVH from stock, no complaints. Honestly, if my PSMM fails again, I'll replace the AWR with an OEM one again. I'm getting old, and when I was still in my 30's, the NVH was cool. I'm 46 now, and like me, that shit's getting old.
For the transmission, I *just* did that one. I went with the latest "D" revision of the OEM mount from Cox Mazda. It was $20 more than RockAuto, but I have found that OEM parts are generally of much higher quality than "OEM quality" aftermarket stuff. For $20? Meh. Why not get the OEM? The replacement is slightly more complicated that the super easy PSMM and rear, because you have to pull the battery and battery box. You cannot see the mount to inspect it without doing this. Also, have a strong as hell impact wrench or really long assed breaker bar to get the main bolt off. That bastard is ON THERE. When you put it back on, don't forget to use thread locker and torque to 90 ft.lbs. You DO NOT want that bastard coming back off on you going down the road.
If I were you, I'd go ahead and change all three. If the rear or PSMM fail, it sucks, but no real way to damage the car. If the transmission mount fails, it can really screw stuff up, because at that point, the only thing supporting your engine and transmission on that side is the CV axle! NOT GOOD.