I don't see how you can even know you want to have a lasting relationship with (platonic or romatic) and you haven't even had a date yet.
I've done both. You kind of already know if you're going to sleep together before the first date, so to call it a date is just a formality. You can get sex without all that. So, if you like someone enough to date them, then wait. Waiting with someone you really like reifies the intimacy between you two, even if the sex itself isn't that great.
If you sleep together the first date you run into the issue of being labeled as easy. The other person thinks, 'if he did that with me, he'll do it with others.' All the while, he disregards the obvious fact that he did it as well. The hypocrisy doesn't really matter because he's glossed over the 'getting to know you' part and put you in the 'fuck buddy' pile.
Last piece of advice: don't think you have to model yourself after any gay lifestyle. If you treat others with respect you'll find the kind of guy you WANT to wait for.