are you still trying to sell the female?
i would keep her mate,once your male matures it will be so much better having 2 females for him and it will double the chance of succesful breeding
now i have 2 females the big one is not taking anywhere near as much punishment
theres a good chance the green will not like a gar
i grew my silver aro and spotted gar up together since they were small and it still did not work
i suppose its trial and error tho ive seen it work for other people
They do get big, however in aquaria they apparently get to arround the 2 foot mark (actually, that is big ) allthough so should your pbass so you could go with one. Being australian though you would have a hard time getting hold of one over here.