It doesn't have actual paddles per se but it does have buttons on the back of the wheel where you'd expect to find paddles, just to make that clear; the stuff you can buy are entire optional aesthetic upgrades as far as I can tell. There is the awful clicky sequential stick too but that sucks. I've always said that the very best mod you can do to a DFGT is replace the pedals with a set from a G27, that's because all the other pedal mods tend to look hacky and don't work as well as the G27 pedals, which you can also upgrade with a load cell and/or stiffer springs should you wish to go crazy. You do have to rewire the G27 pedals but that's pretty much trivial if you own a screwdriver and know how to read!
Yes, you lose the shifter (but for GT5 with the terrible clutch that's no big loss, to be honest, but for PC sims I would take the G27 over the DFGT any day of the week for this reason alone) and the leather wheel, but it's cheaper for a reason. The basic feedback mechanism is largely the same though so you're at least getting that much from the G27 with the DFGT.