Satanoperca jurupari with gravel. Please, share your honest opinion

[bela]

My main tank now is fitted with an undergravel filter and...gravel.

I cannot change this setup nor do I really want to do it.

The thing is that I have found a store near home that has some Satanoperca Jurupari in stock. 

This is a fish that I have not seen in stores for ages and would not mind buying right now. In fact, I would love to have some.

Some people say that a sand substrate is a must, some say it is not.

I will be grateful for all comments but, for obvious reasons, those coming from people who have kept Satanoperca/Geophagus with gravel (if there is anybody) would be most appreciated.

Can it be done?

Would the fish be just fine or not?

Thanks 

[bela]

nobody?