Hi Liam,
The beerbera is great in bottle, lots of carbonation, like a kind of red grape prosecco, it's a little more demanding on tap, it really is more of a wine than a beer, plus they intentionally under-carbonate it in the keykegs for fear of explosions and the like...
The brewery list is as follows:
Loverbeer
Almond 22
Barley
Extraomnes
Foglie d'Erba
Montegioco
I've also spoken to Italiacatessen who are the importers for Birrificio del Ducato, they are open to the idea of asking them also, but I'm not sure if we'll go ahead with that, the square is quite small and six breweries, plus food stands and music would leave not so much room for the public already.
I'm in discussion with them all at the moment about which beers are available for the festival, but there should be at least three being presented by each brewery.
The way it looks at the moment is that each will have at least one special and/or limited edition beer on show alongside their more basic beers. Except for Loverbeer, as he only makes "special beers and extra special beers".