I use a Lee Collet die (the std 25-06 works for AI's) for neck sizing. A Redding body die for about every 3 reloading, and a RCBS Competition Seating die(again, the std works for AI).

I ended up with this set by catching different pieces on sale at Midway.

A standard 25-06 AI set from Redding or RCBS will work fine.

Much more important is to make sure that you get at least a 26" barrel for your AI. Anything less and you won't see it's full potential.