To answer your question they will get along with each other. Earth Eaters do perfer to be in groups (5+) of there own. So getting 1 jurupari and 1 steindachneri would not be the best combo. Since you are going to up grade you could have groups of both! Depending on how soon you are going to upgrade you could have schools of both but this also depends on the size of the fish you are starting out. If you have to choose between the two I'd go with the steindachneri because they are harder to find and a neat mouth brooding earth eater!