The trouble with making lead more common is that plain EU reactors then become too cheap (lead is the main ingredient). What I've done is use Minetweaker/CraftTweaker to change the recipe for RPV:
Code
recipes.remove(<ic2:resource:14>);recipes.addShaped(<ic2:resource:14> * 12, [[ <ore:plateLead>, <ore:plateLead>, <ore:plateLead> ], [ <ore:plateLead>, <minecraft:stone:*>, <ore:plateLead> ], [ <ore:plateLead>, <ore:plateLead>, <ore:plateLead> ]]);
(yes, I changed it to a single stone surrounded by lead, to remind myself that this wasn't the original, you could instead just make it *8 for about the same change)