How many shows do you play in one year? If it's less than 10, then it's not worth getting something that will become obsolete soon after. I'd hire a dedicated sound man with PA and let him stress about everything.
I personally think you're probably gonna get in over your head by buying, storing, hauling, learning to use, and running all that gear. Plus if some of you in the band are retired I'm guessing you don't want to be lugging a ton of gear to every show. I'm 42 and in good shape, and I don't want to deal with that much gear before and after playing 1 set, never mind 2.