OK, so there is really no problem with the sound the
Remo's are producing, just that you want to try something different.
The Ambassadors are single ply heads so you might have had some ring or overtone when using them. The Emperors are two ply heads which will cut down the overtone a bit but it probably is still there to a degree.
The next step in the progression would be a dampened head of some sort that will give you the sound of a classic rock drummer without taking away all of the tone you would need for the jazz. That being the case I would tell you to try an EC1 (because it is single ply with a dampening ring it will still give you some jazz tone) on one of your smaller toms first and see if that gives you the all around sound you are looking for.
As for the snare the EC Reverse dot will give you a similar sound to the Emperor x, but if you are looking for a little different sound you might consider the Genera HD Dry. This will give you a great sounding rimshot and a little more focused
attack.
Where the bass is concerened the Powerstroke 3 is a single ply head with a light dampening ring built in which will be pretty lively sounding. The similar
Evans would be the the EQ4. If you want something a little darker with less sustain you might consider the the EMAD which is also a single ply but comes with a couple of different sized external dampening rings to so can adjust the
attack and sustain.
Now the last thing left is the reso side heads. This is what I would suggest that will work well with what I have mentioned above.
Snare - Hazy 300 reso
Toms - G1 Clear
Bass - EQ3 Reso
OK, so to sum this up....
This is just some info for you to use to decide what you want. You may not like the sound these combinations give you, that is why I suggest to try this on one small tom first so you dont have a couple hundred in heads you don't like. I have become partial to
Evans in the last couple years after being a
Remo guy since I started playing.
There are drummers here (Bo comes to mind right off the top of my head) that have done exactly the opposite and are now
Remo players. If you are thinking you might want to stay with
Remo, these guys can offer some valuable info about which combos you might try.