Have a great time on your MR!! All of us have our own 'favorite' places to eat while in SIN, but some names continue to crop up on these threads over and over...

Do a search for Food in the SIN forum and you'll be overwhelmed!! As for Chili Crab, I personally like the Esplanade location of No Signboard as it provides great people watching, is convenient to most hotels and has some really good food.

I think you're referring to the LongBar at Raffles Hotel. If so, I'd advise against going there for lunch (if they even serve lunch). There are other places to eat at Raffles such as the Tiffin Room, but again - I'd advise finding what sounds to you to be a good "local" Hawker place.
You'll find many, many recs here on the SIN board.

Lots of people swear by Tiong Bharu, and its very very good. You might want to hit the LongBar at Raffles for a Singapore Sling at some time, but go local for lunch.

Best, Dave