In regards to the leadership feat, you may opt to take an intelligent item. My basic question is 'why?' Say you get leadership at level 7. The intelligent item shows up and caps at 25% of wealth per level (23,500 or 5875 for us math challenged). 6k gets you a couple ability bumps, speech, and a second level spell once a day.
What happens when the character levels? There is no chart for intelligent item level progression.
Basically it boils down to a cleric. 11th level gets himself a little pocket cleric who is level 9 (max leadership score). He can cast 1 4th level spell, 3 3rd, 3 2nd, 3 1st. Those 4 abilities right there already overshoot the intelligent item cost (37,600gp vs the 25% of an 11th level: 20,500). And then there's feats, class abilities, etc.
Unless there is some way intelligent items level as per every other cohort...there is absolutely no reason to take it.