Ok, I understand about the mouldings and shaving now

) I don't think I'd bother putting new bumpers etc on my car without getting rid of the moudlings, they're kinda dorky..
As for just replacing the front lip.. I'm not entirely sure what the lip is. I thought it was the front bumper until I just had a look and now realise its like a skirt under the front bumper. But my mouldings are part on the bumper, so no they couldn't be removed without putting on a new bumper. I don't think I could do the shaving thing either, since the bumpers are just crummy plastic with steel frame reinforcement (according to a friend).
Anyway, here's a pic of my car so you can see what I mean about the front bumper. Thanks for your reply!