[guitarman68]

Hi Des,

and welcome to this forum.
Impedance mismatch can be an issue and discussions vary a lot about this subject.
One simple rule: With your preamp do not go to far under the impedance of the pickup. Better stay above or matched.
Another important thing to keep in kind when using passive pickups in your acoustics: do not use extra long cables. Mine are 10ft Mogamis.
An electric guitar amp will not be able to reproduced the complete sonic picture of an acoustic guitar. So I will recommend an acoustic amp or a flat response powered speaker.
Many great suggestions here on the AGF: Bose S1, JBL, Elite Acoustic ... I love my QSC K8.2. QSC CP8 is as wonderful at a lower price.
When it comes to chosing the right preamp, you can not go wrong with what already said: Baggs Para or Fishman Platinum Pro EQ. I add RedEye and Grace Alix.
If a 2-channel preamp is what you need when using both acoustics on stage, RedEye 2-channel or the pricey but wonderful Grace Felix is what I would recommend.
And ToneDexter is always worth taking a look at.