Stock wires... I would go about 50-75k.. since stock wires tend to get brittle and crack.
Aftermarket.. about the same... and aftermarket wire should hold up better.
You can change them where ever you feel like... I know guys that do it once a year... just really depends on the owner and the condition of the wires.
[B]1951 McCormick FARMALL M
2007 MINI Cooper S Turbo... new project car
1998 Chevy 3500 Ext cab, long bed, 4x4, duelly, turbo diesel
2004 Harley V-Rod.... sex on wheels
2011 Harley Electra Glide Ultra Limited