You can probably get great rates at the Venetian for playing in the tournament and staying on 11/12 and 11/13 nights. I don't know how much time you are thinking of spending there, but it's something like $119 per night for those two. As far as tournaments go, I don't know - it's my first time, too!
I think they are all good, but the Mon-Thur ones are more reasonably priced (~$330) and the Fri/Sat is something like $550. The weekends ones probably fill up faster, but they also probably have more weak players.
Keep in mind sign-up starts the night before at 9pm (and some other sources say 6pm). Definitely don't wait until the day of to sign up. I have read horror stories about alternate lists.