We keep Suris, along with other types of Geo...
They are reasonably what I would call slow growing... We keep them in around 26-28 degrees, on a sand substrate... actually Daltons Propagating Sand is their substrate in their tank. They like to sift the substrate, as this is what they do. So having a finer substrate is needed. Ours have been fine in a planted tank, they will not go around tugging at plants and deliberately tearing them out, if there is enough space given for substrate sifting and plant the plants well and have even some rock work or something similar around the bases, then things should be fine and dandy, our guys have never touched plants. We have kept Suri along with other types of Geo, medium sized to large Tetras ie Columbian Tetras etc, Catfish, fancy Plecos, they are a fabulous fish and have outstanding beauty once mature 8) They can be a little bossy but generally we have found ours pretty laid back 8)
How big is your tank? And I would stick with either 2... or more than 3 as a number in the tank... You mentioned you wanted 3.. If you were lucky to get two out of that 3 being different sex... the 2 could eventually pair up, then the other one may get a hard time if seen as in the way if the others infact want to spawn.