Hi there, and welcome to CS!
At the $25-30/kg mark, you will certainly be able to find great coffee. I cant believe that you would even consider mentioning Lavazza ... I mean, seriously ... from your post it seems clear that you can taste the difference between stale and fresh ... is the idea to trade off the well-recognised brand name? My advice would be to get a bunch of coffee and try it out on your machine. I believe that the San Marinos steam milk really well, but tend to run really hot, so you would need a blend that could handle that.
I dont know what sort of pace you intend to have, but I would not ever consider matching a mazzer mini with a two group machine. The mini delivers great grind quality, but it is kinda slow and prone to over heat if your get a rush. Mazzer grinders are built like the proverbial brick s#$%house and are well worth spending the coin on. I have heard from a bunch of professionals that they constantly get service calls for cheaper grinders like the gino rossis, but never, ever for their mazzers. Im currently using two mazzer majors and a mini at work. The majors strike me as quite good value for money. $1.2k or thereabouts, but they seem to grind three or four times as fast as the mini and twice as fast as the super jolly. Id imagine that this grind speed would be important for a cart type scenario, where people are standing there waiting for a takeaway cup, instead of sitting down leisurely and waiting for a paper. You would have no hope of grinding to order with a mini if you had three or so customers in a row.
Im working at Maling Room cafe at the moment and we get a lot of cafe owners to be coming through to speak to us for advice ... dont know why. St Ali is probably the biggest coffee roaster/cafe owner/operator/ barista hangout in Melbourne. Well worth making the trip to see how its ideally done.
Anyhoo, best of luck in your adventures and if you have any questions, Im sure that someone around will be able to help.