Cichla's get pretty large..you would eventually need a bigger tank for a full grown one but in the mean time if you just wanted one for a bit or just wait to upgrade it will work for the 125G..but i am gonna ask what you mean by the second part??
how big do pbass usually get i have a 400 gal with
2 albino O's - 8-10 inch
2 tiger o's 7 inch & 12 inch
1 peruvian O 12 inch
and 2 cascadura - 5-6 inch (fully grown)
4 6 inch unusual pale orange "schooling fish" look kina like a barb