Wakins are double tailed common or comet goldfish. They have the same requirements as common goldfish do and grow to the same size. They just have two tail fins. 45 gallon will eventually be way too small for 4 of those guys.
Actually, rubbernose like to be in schools. They also should be in fast-flowing water, which goldfish don't like. I'd suggest having either the cold water loaches or snails.I would not recommend a dojo loach for a 45 gallon. They can grow to be a foot long. I'm not sure what a walker goldfish is. Is it a single tail or a fancy? Either way, your tank is pretty well stocked, goldfish need high water volume and lots of space.
A good small bottom dweller that would work in a tank that size and with cold water fish is the bulldog or rubber-lip pleco. I keep one in my 90g with my fancy goldfish. They're pretty shy but once they get used to the other fish and stuff they'll come out and be cute. They like caves. Mine especially loves to hang out in the rock piles. They also like zucchini like bristlenose do, but will eat pretty much anything.
Actually, rubberlip plecos are very territorial and having two males in a tank can mean lots of fights to the point of one killing the other. Even having a male and female together can cause friction when they're not breeding, which is very difficult to manage in captivity.Actually, rubbernose like to be in schools. They also should be in fast-flowing water, which goldfish don't like. I'd suggest having either the cold water loaches or snails.
Schools of 6-7 is best for them, it keeps them happy and reduces aggression.Actually, rubberlip plecos are very territorial and having two males in a tank can mean lots of fights to the point of one killing the other. Even having a male and female together can cause friction when they're not breeding, which is very difficult to manage in captivity.
And while they do like cooler, highly oxygenated water, they do not need a fast flowing stream. Frequent water changes (which you should be doing with goldfish anyways) and a decent flow or splash on your return is more than enough to keep them healthy and happy.
That's what I'm talking about.....Are we all talking about the same pleco here...Chaetostoma-whatever they're named now?