Due to the precision placement of switches, knobs and jacks, I opted to order this panel from http://www.bigbluewave.co.uk/resynthesis/resynthesis_home.htm. It's a bit more pricey, since the panels are tooled in the UK. For this module, I'm glad I did.
I generally purchase a blank PCB and source the parts myself from various vendors. I like to use Ebay.com the best, because they offer the lowest prices with free shipping direct from china. Sometimes I use Mouser.com for hard to find, specific items.
I buy resistors and capacitors in bulk, to have on hand when I need them. I also like to keep an assortment of jacks and pots around for immediate access.
For a sequencer, hexinverter.com has made this project even to beginners. Some of the parts should probably be sourced from Mouser.com so that they fit the pcb just right. I have made a modifications for external reset control and external pause control. I don't use these features often, but they are nice to have around. I have chosen to omit the internal clock of this module as I will be using an alternative clock source.
gLike