If you want Electric Yellows, you'll need a dedicated Mbuna tank (type of African Cichlid they are) or atleast a dedicated Lake Malawi tank (which would include Peac0cks). Alot of Mbuna are herbivores or omnivores needing a heavier plant matter diet, so they like to eat plants. They also dig....so they aren't very plant friendly.
(for an article on Peac0cks, go
here and click on the article name....stupid filter messed my direct link up)
I found this page on them....not entirely sure if the info is 100% correct or not, but a quick skim and it looks pretty good.
http://www.thetropicaltank.co.uk/malmbuna.htm
Mbuna are rock dwellers, so you are looking at a tank with alot of rockwork.
They are beautiful fish. Some can be pretty aggressive, so you have to be careful what you put together in the tank.
To cut down on aggression, I suggest an all male Malawi tank:
http://www.cichlidforum.com/articles...ale_malawi.php.
I still think it would make a fantastic planted tank though!