My tuppence is, not many singers own a PA that can take a full micing of every instrument. If something blows on the PA who is paying for the repair? You should also state what type of music or songs and how much you realistically expect to get per gig and the distance you are willing to travel to get 100 gigs per year to allow people to decisde if it is for them. I think this is too much as most gigs are weekends and this would book up every weekend, which would make gigging a chore.
I would recommend you break it down into essential requirements and preferred requirements to give you a chance of getting a decent amount to pick from rather than having only a small number apply. Another option could be to define what success looks like for you (which you have pretty well defined) and then say if your vision of success looks anything like this then contact you. I would use woolier terms like sensible, reasonable, practigable etc.
From my experiance for pub gigs the back line does provide some of the volume that then allows for a smaller PA. There is also the dicussion between 50W valve and 50W transistor ;-)
Good luck.