Well, I think you're a little confused about things. I don't want to come across as a jerk at all, but I just want to clear some things up.
First let's analyze everything you said: his clothes. He wears a dark green tuxedo every once in a while, but most of the time, his tuxedo is so dark you can't tell if it's black or navy or another color. His clothes (in my opinion) remind me of... well... the Penguin, especially since he is the Penguin. If you really want to make a stretch, his clothes are more reminiscent of the Riddler than anything.
His hair: I don't really understand how anyone thinks his hair is supposed to look like the Joker... the Joker's hair is almost always messy, but slicked back in almost a 1940's style manner (apart from Heath Ledgers version). The Penguin's hair is in spikes, going down on his face, almost in an emo/goth sort of way, something that would be popular in a very place like Gotham where the style of everything is Gothic 1940's punk. Also, his hair is supposed to look like a certain Penguin... can't remember the name.
He's always smiling: Not always. And not only that, but when he does smile, it's not a creepy "crazy" smile. It's that kind of smile that makes you wonder what someone might be up to. If you've played Arkham City, you'd know that the Penguin in that game also smiles and laughs a good bit. But, it's not because he was influenced by the Joker; it's because he's a slimy mob lord, always wanting to get the best deal he can get, even if it means cutting other people out of the equation. And that's why he's smiling; he's suspicious.
His relationship with Gordon: This one is probably the most different once you think about it. Batman and the Joker have a relationship where Batman can't kill the Joker, but he'd do everything he can to never see him again. He can't stand him. The Joker loves Batman, but in a way to where he wants to mess with him and see how far he can really push him, and if he can break him. Gordon and Penguin are different. Gordon doesn't like him, obviously, but he can tolerate him, because he is useful (as seen on the newest episode). Penguin, in my opinion, isn't after Gordon because he wants to push him over the edge or do horrible things just to get his attention. I think that the Penguin really does appreciate Gordon, and really appreciates the fact that he saved him. Sure the Penguin is a slimy coward who doesn't have a real moral compass, but he can recognize and respect someone who's genuinely a good person, and has good intentions, and I think he appreciates Jim for that.