Well not sure what you mean by "door poppers" the way most guys do it it to put an electric solenoid in the door and a button out side somewhere to open the door........
If you run relays to handle the load you can run just about any switch you want.
I've put micro switches in the moldings or mirrors also have put starter buttons in the wheel wells or under the rockers so its really up to you what you want........ They make magnetic switches that you just pass a magnet over and it pops the door they also have what is called a tap switch that you mount close to a window some where ( close but not where you can see it)
then to open the door you tap on the glass by the switch and the door opens..... from what I remember you can change the coding on it so the number of taps and the time in between taps has to be right for it to work......... just some ideas

If you don't want anything electrical you could hide a pull cable in the fender well...... there usually used to get in the car if the battery goes dead ona car with electric doors

Also I seen guys leave the key lock in the door and take the handle off then hook it up to the door latch so when you turn the key it "opens" the door........ but don't get out and leave the motor running and close the door......... cuz you can't get back in ..... Don't Ask!...... alls I can say is mother nature called and dam it was cold!!!!

Hope some of this rambling helps

MM64

www.rgkustoms.com