Definitely book two rooms. They charge for extra people in the room anyway. (If you tell them.)
There should be some offers for September soon. Try this link

Travelaxeis another good source of cheap room rates.

For some funny casino reviews try Cheapo Vegas

Book 2 rooms, you will be far more comfortable.

We also go in September, what dates are you planning on going?

As an idea of the kind of deals you can get, the MGM Grand is offering Grand Tower rooms for $69 on Monday-Thursday 17th-20th September. Weekend rates will be much higher than that.

We managed to get a Celebrity Spa Suite for $144 per night Sat through to Friday of that week, approx £73 a night, cheaper than a Premier Travel Inn in York City Centre!!!!

The link provided by the poster above will assist greatly. Decide on your dates and then just click on each hotel, see what takes your fancy.

We have stayed at the Luxor, New York New York and Excalibur so far, and obviously MGM next month. Our fave out of those is NYNY, but the other two are fine, Excalibur is particularly cheap midweek.

If you need any further help just post here or PM me.

Cheers