I have experience with three different types of flowmaster mufflers.
1. The regular 40 series 2 chamber muffler. This is a good all around muffler, "the original flowmaster sound", and puts out a decent exhaust note on most any car. I have a set of 2 1/4" 40 series on my 67 camaro and they are dumped at the rear. I don't have any drone with these mufflers, and they aren't that loud in the car. Here is a sound clip.
http://people.clemson.edu/~jaander/videos/100_2556.mov
2. Flowmaster Super 40 mufflers. I was after a more agressive/deep sound with my 'Cuda, and these mufflers definately delivered. I have a 3" setup on this car, and they are also dumped at the rear. The car has a pretty souped up 340 in it and the mufflers make the big cam sound even better
sound clip of these
http://media.putfile.com/cudasuper40driveby
3. Flowmaster one chamber race mufflers. I have these on my 99 Camaro SS with a 2.5" size pipe, but I put an x-pipe on this exhaust. It also has a very deep sound, and it screams at w.o.t. However, they do drone some in the car, but it doesn't really bother me that much. Here is a sound clip of it.
http://people.clemson.edu/~jaander/videos/100_1945.mov
I hope these help you out some. If I were redoing the exhaust on your car, I would probably choose the super 40s. They are the most refined out of the three mufflers listed here, and have all of the great sound, without the drone.