I have a Moog Low Pass Filter (with expression pedal) and a Zvex Woolly Mammoth, when I use them together (expression pedal controlling the cut off) it soooo synthy, and exactly what John Davis of NERVE uses, but that along with my Octron and you have synthy good ness at you feet
Many fuzzes work with the Low Pass Filter to create a similar effect, but the gate just sounds great with it! So if you want it a bit cheaper, I'd get the OC-2, some cheap fuzz (big muff variant maybe?) and the low pass filter. You won't be disappointed.