Two brothers and a bike brand whose name begins with "G" - could be Guerciotti. They had more than just two frames in the lineup, but, given your hazy recollection, you may be misremembering that detail.
From
this page:
"The history of the Guerciotti brand started in 1964 when the brothers Italo and Paolo Guerciotti – at the time road and cyclocross riders, respectively – opened a small workshop on the outskirts of Milan."