Hi All, so after my band's first gig, I realized that I needed to up my power for next time. I play electric and acoustic guitar and normally use just my behringer acx1800 amp for vocals and acoustic guitar and my fender amp for electric guitar. So here are where the questions begin. I'm thinking of ditching both amps and getting a PA system instead.

I've heard that you can't just plug the guitar directly into the PA speaker because the tone sounds flat and like someone throwing up into a tuba. I normally use a Vox Tonelab LE for effects and amp sims, so I was thinking I could go guitar -> tonelab -> PA. I don't know about mixers or DI boxes and whether I need them in this, but essentially I would be plugging the microphone into it's own multieffects processor (vocalist live 4) and that into the PA. My thinking was that both processors have balanced line outputs to go into the one PA speaker (eurolive B212D) and that this might work.

Then I started reading about needing a mixer possibly and all that. I'm basically trying to not buy stuff I don't need, so I'm wondering if I can get by with the following:

microphone -> vocalist live 4 -> PA xlr input
guitar -> tonelab LE -> PA 1/4 input

Are multiple things not supposed to be plugged into one PA speaker without going through a mixer first? I was under the impression that a mixer would be to take in this case, the guitar and the microphone signal and then combine them into one output to go to the PA, and that's why I'm starting to wonder if I need to buy a mixer too.

I know that's a lot of questions, and I really appreciate any help you guys can give me...thanks!
- Fender Strat (Black on white) with Duncan Quarter Pound Staggered Pickup
- Celebrity Ovation acoustic

- Vox Tonelab LE
- Line 6 Verbzilla
- Boss DD-2 Delay
If by PA you mean powered PA speaker then yes you'll probably need a mixer. Mixers can be found cheap and really make hooking up equipment and setting levels easy. The Behringer mixers are good. Or at least the 1002FX that I have is good.
Stay far away from Behringer mixers. A band I played in a few years ago went through four of them in as many gigs. And these were the 24 channel models costing several hundred pounds, ones that were supposed to be 'higher end'. We had everything from individual channels not working, intermittent power cutouts and high-pitched electrical noise coming through the board. I've also had my fair share of venues using them and suffering issues as well.
Fender AVRI '62 Jazzmaster, Fender Gold Sparkle Strat (custom), Custom Swirled Roswell Rhoads
Marshall DSL15H, Weber Speakers, Fender Champs (x2),
'63 Fender Reverb, Mosrite Fuzzrite, Joe Bonamassa Fuzz Face, Whiteface RAT
Vintage Tubes!
^Well experience with 4 trumps 1. But mine is several years old, cost $60 used, and is solid as a rock. Even ran an amp's speaker out into the mic input once by accident and it didn't hurt it.

By contrast I just purchased 3 Mackie mixers last week and only had one that worked.