In Pathfinder, is it possible to create an item using the Craft Wondrous Item feat, that provides a skill bonus to Spellcraft for creating magic items?
What would be the most appropriate item and cost?
Usually such magic items would confer a competence bonus to said skill. For crafting stuff, I would suggest either gloves, head, or ring slot, but that's what makes sense to me (and if you're looking for suggestions for your GM, he/she may have their own opinions).
As far as cost goes, I think 2,000 gp to 5,000 gp would be appropriate assuming it only applies to Spellcraft for creating magic items (versus say identifying a spell).
Example of a magic item granting craft skill bonuses: Ring of Maniacal Devices
Hope this helps!
The amulet grants its wearer a +5 competence bonus on Spellcraft checks
Being a magic item from a module, you may want to check with your GM if the item is allowed.