Tiger barbs are semi aggressive and buenos aires tetra are aggressive towards plants.
Generally tetras and tiger barbs dont mix as tiger barbs can be nippy. If you did mix them id suggest getting a big group of barbs and buenos aires as both are shoaling fish and in large groups 15-20 of each the aggression will be spread out and evenly distributed instead of one or two fish being bullied. If you can get more females of both than males.
Then watch them to make sure they arent shredding eachother.
I wouldnt add any other kind of tetras. Congos fins are too long and they are shy, serpaes while nippy fins are too long, skirys fins too long will get shredded, columbians too small all other tetras too small.