I don't know any perfumes to recommend as I am not familiar with the Lacoste one, but I think you need to worry less about offending sales people. If the salesperson is not showing you perfumes that suit you, you can simply say, "None of these are what I was looking for. Thank you for your time, but I won't be buying any of these today."
Or if that is too difficult for you, say "I want to walk around a bit and see how this scent develops on my skin." Then leave. Personally I think it's always better to let a fragrance develop before buying anyway. I avoid buying immediately-- it isn't possible to judge the fragrance fully until all the notes have developed. You can always return to purchase later if you like it.
Don't part with your money if you aren't happy with what you are buying!