OKC only has 15 buildings diagrammed so far. I don't have the patience to do it, so I'll just point out some good ones. All of these buildings are already in the SSP database, they just haven't been diagrammed.
Listed here are two historic buildings, twin suburban offices, a CBD residential building, and an office designed by I.M. Pei.
Here is OKC's current diagram:
http://skyscraperpage.com/diagrams/?16962973
Architectural Gems to Diagram:
Colcord Hotel (Under renovation into boutique hotel- built 1909)
(can't find any good pictures, but here's Emporis:
http://www.emporis.com/en/il/pc/?id=122522&aid=8)
Skirvin Hotel (Under renovation into Skirvin Hilton. Built 1910)
Some easy suburban OKC towers to diagram:
Oil Center East/West Towers (It's a two-for-one deal)
Important downtown buildings
Park Harvey Center- Being Redeveloped into 170 apartments (Grayish building at center)
emporis-http://www.emporis.com/en/il/pc/?id=122532&aid=8
Corporate Tower - Designed by I.M. Pei. It's weird-shaped so visit Emporis to see all of its angles. Is this where Mr. Pei's fascination with triangular prisms began?
http://www.emporis.com/en/il/pc/?id=122551&aid=8