Personally, from having a fluval 306 filter i dont rate them too much, not bad but theres better out there.
Im currently using an fx6 (£220~£250) and a tetra ex1200 (£99) both are brilliant filters and come with media.
filter placement isnt all that essential unless your opting for UGF, my fx6 intake is on the far left deep in the tank, the outflow is just to the right of it tilted towards the surface for great surface agitation.
My ex1200 is opposite this on the far right with the intake closest the right side and the outflow i used the spray bar that comes with it.
water flow is also very good to have with cichlids in my opinion, so i use a Hydor Koralia powerhead to create more water flow, this is on the right of the tank pushing water towards my fx6 so it collects more waste.
Filter choice is ultimately down to you, these are just my opinions
Also a very very large amount of rock is better for mbuna, so be sure to check what weight your tank can take, and if needed use egg crating before adding sand to even weight distribution.
When scaping your tank beware cichlids dig! they pick up sand and spit it to sift for food and redecorate, ensure rocks are securely in place, you dont want a rock slide smashing your glass!
Note that the amount of rock you put in your tank will affect its water capacity greatly, so assume a litre value that the rock takes up then calculate stock to the remaining water space you have
If your not looking to breed a 1-5 ratio isnt essential, you could opt for a male only tank.
If your in the UK i highly recommend tonysafricancichlids.co.uk ive ordered from him and he breeds great lines of mbuna and aulonocara, many of which your standard fish store just doesnt stock.
Sorry for the essay and hope this helped, i know you only mentioned filters but a little more advice is always good, unless you already knew all that then i just wasted 5 minutes
