Wow, that is a SERIOUS change there man. I would think about this a little harder, as going from that many Discus to Crenicichla is gonna be some serious changes. Crenicichla are aggressive, predators, and can be a pain in the butt some times. Totally different end of the spectrum when it comes to Discus. You're not gonna be able to keep the same amount of pikes as compared to your discus as well. In a tank that size, one pair of Saxatilis or Dwarf pikes will work pretty well, but any more than that and you will be pushing your luck. Do you have any other tankz?
Regarding the plants, no problems. Crenicichla are some of the few SA cichlids that can be safely housed in a planted, well decorated tank. They generally aren't diggers, and don't tear up the aquascaping like most other cichlids will, so no worries there.
Seriously think about this some more, if you DO decide you want to go with Crenicichla, GREAT! Then we can work on it from there. If not, no worries man!