My questions is, I am going to install a after market turn signal switch. I have a 6 volt system so i need a 6 volt flasher, i plan on running the front turn signals to my parking lights. What else do i need to get besides the 6 volt flasher.
Read the turn signal switch instructions first. That should help figure out what is needed. Somehow you need to wire the brake lights through the turn signals so they work at the same time.
brake light switch is going to run to the turn signal switch instead of back to the brake lights. the wire that ran previously to the brake light switch will be connected to the "right rear" wire, from the turn signal switch and the left rear brake light wire will be disconnected from the wire harness and extended to the "left rear" wire, on the turn signal switch. so to answer your question you will need about 12 ft of 12 gauge wire.
I imagine its the type that attaches to the column using a hose worm drive clamp. If so, make sure you have a good ground connection between the clamp and the column.
if you want the front parking lights to still be, parking lights, you will need to replace the sockets with a dual filament type. and run a left and right side wire back to the turn signal switch. so add to the shopping list 2 sockets and bulbs and 15 ft wire.