lots of the models maiovvi mentiones are modelled in the digitech distortion factory pedal:
http://www.digitech.com/products/Pedals/DF7.php
I got it aswell, and it sounds, to me, okay. you got 3 modus (selecting while powering) 2 x mono out (1x amp out + 1 x mixer out + vintage amp sim added (like fender amps). and 2 stereo modus. (mono in stereo out)
I like the 3 band eq on it so you can finetune it for drums processing...great for gabber and hardcore hehe. This thing sounds great on a TB303 (or clone)aswell really nasty. And the different models gives you a wide range of choice, because each type of sound needs a diffrent type of distortion with different harmnocs andso, for drums you need a low end disto and for synth a more brite one and less noisey.
But much depends on what you are gonna process, for buss efx or masterinserts, there are some other stuff that works better. I got also a culture vulture (10 x tubes inside) dual mono rackdistortion that is top off the bill stuff, but sounds really great and warm. But thats maybe too expensive for what you are seeking. And its not merely a distortion but also a tubedriver, but if you switch it into overdrive with a knob it is instant apaocalypse hehe