Yeh scrap my idea, spoke to maximus online and he told me about how there not armoured cats and wouldnt do well with mbuna (Yes, african cichlids), looks like im stuck with either BN's (Zzz) or syno's.
My 3" goldie is in a 4ft tank now but willmove into my 5ft when he grows up a bit. From what I can gather tehy can be very territorial and need plenty of space, especially is sharing with other plecs.
Most gold nuggets you see in lfs are not the 14-15 inch ones they are the common 7-8 inch, so I was guessing that was the species you were purchasing. I wouldn't put it in with th africans for sure, but I agree with xingumike on the synodontis.