We can fit the Renaissance into your budget. Easily. You may not think so, but I know so, and you don't even have to get a fully prepaid rate.
I want you to go to LastMinuteTravel.com. LastMinuteTravel.com is a "unpublished rate" website, meaning that they don't reveal the name of the hotel until after you book. However, they do give you photos and some helpful clues to determine the identity of the hotel you'll be getting.
So enter your dates, number of adults, and click "Search Now." On the left side of the search results, there is an option to filter results. Click on the four gold stars (there should be 18 hotels listed) and then scroll through the list of results until you find one listed at $155.26 per night for a standard room (it says it is 5.18 miles from the airport...). Click on "Photos" and there should be twelve photos. The photo in the last column, second row is of a event room and on the projector screen in the front of the room, do you see the Renaissance logo, such as this link below, only in white on a black background?
Now click on "Features and Amenities." It says that it is has 807 guest rooms. Now look on the renaissance website, and it too, says that the hotel has 807 guest rooms. LMT also tells you it is just 1 block from the convention center...so hopefully by now, you can rest assured that that hotel will be, in fact, the Renaissance that you so desperately want.
Plus, it is well within your budget - about $50 cheaper than your maximum budget!
Hope this helps, and any ?s, please let me know-