males tend to have bristles while the females have none or very small ones...nothing in your tank should bother the pleco and the pleco shouldn't bother them either
Bog wood is a must IMO, as they will spend all day on it sometimes, its good for them, also they will be fine with your other fish, females get bristles like males do the only difference, is that males get bristles growing through the middle of there head where as females get them only round the edges.
Personally, I find them very hardy once properly acclimatised, and reach a decent size (2 inch+). As with most bottom feeders, you will need to make sure there's plenty of oxygen (more surface disturbace if your tank is fully stocked)
I think I just have 'common' bristlenoses and my female does have bristles all around her chin and 1 on her nose (bit odd). The male has loads more.
The male does not seem to bothered by the bogwood but my young b.n. is always on it and the female is on there a lot.
I have the same tank as you which I originally got 2 baby b.n. for to keep it clean and provide a bit more interest. They were to be moved on to larger accomodation when they had grown. One b.n. climbed out and died on the worktop and the other kept constantly climbing into the filter housing. After about the 5th or 6th time of getting him out of there I chucked him in my big tank and he has been fine. The reason for the trouble is the closeness of the cable cut-outs and the top of the filter to the water level in the tank. Also there is no cover for the filter box. Even when we made a cover it didnt stop him.....
I know nothing about otos but from my experience i wouldnt put b.noses in that tank especially if you dont have one to move them on too as you will seriously be in by the time you've had them a week.