I have this kit and I use the following heads: Remo
Bass Drums:
Batter - Powerstroke 3
Resonant - Powerstroke 3
Muffling - A medium sized pillow barely touching the reso and batter
Beater Type - Eliminator sharp plastic side
Rack Toms:
Batter - Ambassador
Resonant - Ambassador
Muffling - None
Floor Toms:
Batter - Ambassador
Resonant - Ambassador
Muffling - None
Snare:
Batter - Controlled sound reverse dot coated
Resonant - Diplomat
Muffling - None
Snare Wires - Pure Sound Blasters Series 20-Strand (I am not completely sure on this)
This is personally my favorite combination of heads so far, after experimenting with muffling and pre muffled heads I found my middle ground and decided the more ring the better. I have listened to a few players who have the same kit (poplar would as well) and use pre muffled heads and body pillows in the bass drums and with the poplar wood, it is dangerous to muffle it I found out because it is already such a quiet material. I have a friend with a Mapex birch bass drum and it certainly projects a lot more sound than my export does. It doesn't necessarily sound as fine tuned and clean as mine though, thats because I have spent way more time experimenting and tuning my kit, but back to the subject. I have tested out almost all of the drum set heads on this kit made by remo Remo including the powerstroke 3 and 4, emperor, encore, pinstripe, ambassador, emperor x and I have spent a ton of time tuning this kit as well. I found that tuning everything just past wrinkle does not get you a warm sound on this kit and tuning the drums extremely high make them sound like kegs from slipknot of some sort. So the key is to find the note that each drum sounds best at and check your tuning about once a week cause I guarantee your tuning will be out by then on this kit. I am still experimenting with the floor tom heads, but so far ambassadors have ruled the toms for this thing. I definitely recommend replacing your snare wires if you have the export snare with stock wires, it made a huge difference on the snare. Also the diplomat is very good for the snare side because it gives it a lot more cracking sound than the stock snare heads. I use the pointed plastic beater side because I need it for metal applications, but I have played with each side of the beater and the flat felt side gives it a nice warm sound. The pointed plastic side just give it more volume and attack, so it just depends on what sound you want to accomplish, but for a good sound on this kit I recommend that you just follow what I have listed and you will save much time and money experimenting unless you want a more specific sound.
Well good luck and let me know if you have any other questions, I would be more than happy to inform you on anything I know.