30 gallon long with 1 fantail, 1 black moor, 1 bristlenose pleco?

How does that sound? The tank measures 36" long by 12" wide and 18" high. I will cycle it. I'm still setting it up but I'm getting a Marineland Penguin 350 filter, good for about a 75 gallon tank. I'll do weekly water changes and siphon the gravel at the same time, and I'm getting a cave and driftwood for the pleco. Do you think an adult bristlenose pleco would like a cave better that's 10 x 6.5 x 3.5" or 7.75 x 5.75 x 2.75"? Do they like a little room to move around in their cave or to be more closed in? Anything else I should know about what to put in the tank or anything?