I think you'll be fine. Bally's is a good place to play $1/2 NL and there are plenty of people who will play just as badly as in your NL25 game. The money you've brought (5 $200 buy-ins) should be sufficient and you probably will be able to do all the hours you need each day there with no problem. Bally's is a good location because you can hop next door to find games at Paris or the Aladdin or can cross Flamingo Road and get a similar game at the Flamingo. And the Bellagio and Caesar's are across the street!

Regarding the original post, I love playing low-limit NL at the Excalibur and Bally's. The Stratosphere is also pretty decent and touristy at times and sometimes I'll play the NL $1/2 game at the MGM Grand.