Hi, I have the opportunity to do an event and I need to know which lens would be best. I realize I should have several lenses to work with, but I can only get one. I am currently using a 50mm 1.8 and I do have an 18-55mm. lens as well. I know these won't work, so let me tell you about the setting and maybe you can give me an idea as to what lens would be most useful. It will be indoors (evening) and probably low lighting. There will be a stage and stage lighting. I will photograph speakers and entertainers as well as people as dinner tables. This is for free and they know I've not done this sort of thing before. However, I want to do really well. So...I've heard a little about the 24-70 2.8lens and the and the Tamron 17-50 2.8. Do you recommend either one of these and why? I really need to do what is the most affordable and versatile. Also, would either one of the above lenses work well for beach photography? I use the Rebel XT. Thanks!