selecting the correct rating system in v.2009

Hello LEEDuser community- I need your opinion on the correct v2009 rating system to use for an office project. Here are the stats: -The 6,000 square foot space is in an existing building that has been gutted to its structure. -The space is part of a larger building; but separated from the other areas by a 1 hour rated fire partition. -There will be new mechanical, new lighting, and new plumbing (2 water closets, 3 sinks) systems installed. -Limited amount of new partitions (open office plan) -The existing monitor skylights will be replaced with insulated glazing (an abundance of daylighting). -Other existing exterior openings will remain in place (aluminum storefront entry systems and double hung windows). Based on this, would this be considered a Major Renovation (NC), Core and Shell (CS), or Commercial Interiors (CI)? Thank you for your input. -K