Seriously though, am not sure about the oddballs. it has a half-decent marine section, small-mid selection of cichlids and then your usual "run of the mill" fish.
I have been to Wyevale Garden Centre up in Winsford a few times. They have had a few oddballs in the past, including various puffers. You might want to give them a try.
There is also a place on the Wirral (can't recall the name though sorry
) that has a small selection of oddballs. I know he has a largish puffer (i think maybe a Fahaka) 'cos I fell in love with it when I saw it.
Apart from that I can't really help you any more. Most of the LFS's around the area tend to concentrate only on the more common fish and don't bother with oddballs.
If you do you find anywhere let me know 'cos I wouldn't mid a visit myself.
steve