Peace,
I thought I might add that if you do decide to go to the Mosque, it is very unlikely they will ask or expect you to join in the prayers and pray in the way Muslims do. I would be very surprised if they did this.
If they do it would be perfectly acceptable for you to say no and that you are not comfortable with it and you are Sikh and you dont want to do it. There is no reason why it should cause them any offense, and if it does, they are not entitled to feel that way.
people warning you off because you might be converted are making me laugh lol. if you have strong faith then it shouldnt make any difference, but in the end it is what you feel comfortable with that matters. If you dont want to go then dont, but make sure its for the right reasons and not just because some <banned word filter activated> muslims that you know refused to go to the Gurdwara for no good reason.
sikhlionz you post is appreciated I'm glad your experience was positive, as was mine when I went to the Gurdwara :|