I have an Epiphone Masterbuilt, which has eSonic2™ preamp system, I was wondering if I should buy an amplifier or a monitor (PA system)... Thank you!
It may depend what else you want to do, now, or ultimately. There's hardly a need for an amp of any sort for home playing and practising with an acoustic guitar, whether it has pups or not. So I assume it's for playing in public. Merely playing the guitar, perhaps with others, an amp will do the trick. Especially an acoustic guitar amp.
However, if you sing as well, you're going to need an amp for that - and a mic - and an acoustic amp won't be as good as a p.a, which will also do a good job with the guitar.
There are many amps out there over the last few years which have been specially produced to be used as mini p.as, and guitar amps all rolled into one. And they do extremely well at both. Not cheap, but quality rarely comes that way.
Not recommending any brand - it's not company policy - but one of those would be a best bet, if you need more than just a guitar amp.
Incidentally,(as you mention p.a/monitor); a p.a system in its simplest form comprises mic., mixer, amp and speaker/s. 'Monitors' are an extra, so that the performers can hear better on stage. You could get away with a powered monitor for smaller gigs, instead of a p.a.