Limousine For A Stag Do In London

Me and me mates are heading to london for a stag do and need a limo for the night. We want someone with good local knowledge(wink wink). Anyone who can get us in a few places in the west end will definitely have the edge on this one. Not sure on the numbers yet, we might even need 2. We want to make a impression, we`re loud and up for a laugh so noone too prickly either. Any ideas?