Well i have a Dod 250. Great pedal but its an overdrive, might not be enough for your needs.
I had a Flashback Fuzz, its more like a distortion. A bit crap as well.
The Voodoo Lab i dont know much about, it is'nt germanium transistor so its not aiming at classic fuzztones. From the description it sounds similar to the Seymour Duncan 'Tweak Fuzz'.
Do us a favour and go to the store tomorrow then tell us how great Rat's and Big Muffs are ...