Newbie PA question, I know what I should do, but ...

[Rick6]

Any advice would be much appreciated. 

My mostly instrumental jazz quartet got a restaurant gig.  If our wives knew the money, they wouldn't let us demean ourselves like this. 

I decided, in an attempt to keep the audience more engaged, to sing a couple of tunes.  I brought, don't laugh dangerously hard, a mic stand, a Sennheiser 609 and a plan to plug it into a Roland JC55 guitar amp. Nothing else through that amp. 

The restaurant is like a high ceiling 18x60 or so. We're wedged into the space that a table in the front window on one side of the door would take. If the bass player ate a cookie, we wouldn't have fit. 

I recall hearing two pros, guitar bass and each sang, going into a 4 channel mixer and then into a guitar amp and sounding great in a very small space. So, I was thinking that we wouldn't play very loud, I can't sing well anyway, and that Roland might be enough. 

I put my guitar through a DV Mark Little Jazz which was more than loud enough. 

But, I think the vocals and the announcements to the audience probably had that muffled quality you associate with being wakened in a bus station. 

I also have use of a Mackie 350 and I have a Yamaha MG10/2, an older one with no FX.  I put a Korg PX5D set for reverb only in the FX loop and it seemed to work. 

But, this is a kluge, even for me. 

I could buy a small Mackie mixer for about $150, with more than enough channels and FX on board. 

Or, I could buy a used Yamaha StagePas 300. I just had a gig where the venue had one and even my guitar sounded great through it (line out from the Little Jazz). 

For talking to the audience, do I even want reverb? Or as much reverb as I want for singing? 

Is using the JC55 really that crazy? 

I know about buy once cry once and the risk of going cheap. 

If I buy the mixer and go into the Mackie 350, what else am I going to end up having to buy if anything? 

Thanks for reading this far and for any advice you might offer. 

And, btw, the kluge sound worked and we got a regular gig at that place. 

Rick