Surprise entertainment help...

Hi I've been looking at a surprise for my fiance Dave for our wedding in July next year and really have my heart set on singing waiters which I think he and my guests would absolutely love. I have called around a few places that I have seen on google, but the quote they have given seem to be quite expensive. I don't mind paying the expense if I know they are good, however I'd rather shop around and see which is the best I can get, so I'm just wondering if anyone can help or has any recommendations, I'd appreciate it very much.