Out of the the three companies, I've only heard of Dream Host. I couldn't even specifically find the Radiance one website just because there are so many companies that carry Radiance and Radiant names out there. I don't have experience with any of them, but I wanted to give you a few other pointers.
Keep in mind that large companies have a tendency to see clients as numbers. A loss of an account doesn't affect the bottom line as much as it'd affect a smaller/medium size company. So usually the trend is that smaller firms would work harder to keep you happy. The advantage large companies have is in financial stability.
Your budget is very good for a small site and you should be able to find a very good provider.
My personal suggestion would be to take a look in the offers section here on HostingDiscussion.com. There are plenty of companies that are present on the forum and a lot of them post special/discounted deals not available anywhere else (an extra coupon won't hurt, right?): http://www.hostingdiscussion.com/shared-hosting-offers/
The good thing is that you can see each company's track record on the forum, see how engaged they are with the community, how helpful and knowledgeable they are in their posts. To me that's usually more telling that a review of what kind of service you can expect.
Lastly, why did you choose Simple Machines forum? There are so many other more modern choices available.