I would NOT say that Congo African Greys do not get along with other birds! I live with my BF in which I have two conures a Sunconure and a Green Cheeck conure. I have the two together and for most part things are fine. An occassional squabble, like two year olds, other than that fine.
My BF has a Red headed Amazon and a Congo African Grey. He has both of them in the same cage. and has had for the past three years. They got along even longer. They were only seperated because did not have a cage big enough for two birds of their sizes. They get along great for most part too, but just like with the conures they get squabbling like kids. Then we seperate them for awhile. The Amazon love to be on top of the one cage to watch outside and to be away from the Grey being too pesty, wanting to play, but the Amazon don't want too.
Also as far as you comment about talking. BW the CAG talks up a storm, with or without Baby the RHA. They both bond with each other and also with us. Baby was talking, but after BW got to talking alot, for some reason Baby does not very often.
Funny thing is the Baby also is bonded somewhat with my Sunconure. The Sun and baby are not in same cage, but play on top. They get along fine, just if put them in together he gets TOO amorous, and we are afraid he would hurt her, being alot bigger.
So you could try it. Although I do not know with the Blue Front. All I know about them is they are good talkers. How they get along with other breeds I do not know. I do know our CAG gets along fine with the Red head Amazon. He is very jealous of my Sun. He wants to play with the litte Green cheek but BW is too big, so we do not let him near the GC. He could hurt or kill him without meaning too or realizing it.
Good Luck