Wyandottes are awesome. My second chief rooster for the big mixed flock I used to keep was a silver-laced Wyandotte which I bought off a fancier when said bird was five months old. A big, beautiful, smug, proud fellow who always did his job once he assumed the top position and who never gave me any trouble. I named him Elvis for his, er, portly dimensions.
Anyway, if you're now a first-time rooster owner and somewhat nervous about it, please refer to one of the tutorials on this site about how to train your chicken for showmanship handling and get going on training your cockeral. It's the chicken equivalent of taking your young dog through a basic obedience school class. You will gain confidence in how to handle him and he will learn to behave in a docile and agreeable manner when you have hands on him, which will help a great deal in establishing a good relationship all around and make him more easy to care for in the future. No, you don't have to show him any more than people who take their dogs to obedience classes have to compete in obedience trials afterwards (although quite a few go on to enjoy the sport), but it's a START and the steps/exercises are usually well laid out and easy to follow. I used to advise oh, just handle your rooster enough when he's young to establish a habit of compliance and get him used to the idea that you're going to be a dominate force in his life and you'll have no trouble with him unless he's inherently bonkers and hyper-aggressive (which happens). But that's not enough for new owners, is it? It's too general and assumes you understand basic chicken behaviour. So if that's applicable to you, please do try the showmanship training route. Both you and your cockeral will likely enjoy it.
As for housing, since he's already partly grown up as part of a little flock, it would be cruel to now separate him entirely from the others and keep him as a singleton; he is already socialized to want to be with other chickens...you're just the occasional friend who drops in now and then. If you want to keep him, yet not let him run with the others for fear he'll harass them too much, the best solution is the small pen next to/within the bigger pen option. That way, he'll get to still socialize with the girls and be part of the flock, but in a restricted way. You also then have the easy option of letting him out to run with the others PART of the time...and you might find that he's actually a pretty decent guy who treats the ladies quite well. At the very least, he deserves to be kept through his raging teenage hormone phase, which is when cockerals are typically at their bitey, jumpy, obnoxious worst if they're prone to being obnoxious at all...not all are. I don't remember my own Wyandotte rooster ever going through an obnoxious phase. Never ever. Maybe yours will be the same.
Anyway, best of luck, and hope all works out whatever you decide to do. Have to admit, though...I'll always advise to favour the chicken, so, take what I've just written accordingly.