From the research I've done and dealers talked to, you are dead on with Packs 1-4. The only other one is Pack 5, which is a loaded V8. There are no options there. Pack 4 is $40,000, Pack 5 is $42,000 so you pay $2,000 to get the V8.
No, you've missed the base V8 -- that's the V8 without Technology package. MSRP is $37,250 (or $38,000 with the destination charge). The next package is the V8 with Technology at $42,000 MSRP.
Look here:
http://www.hyundaiusa.com/vehicle/Genesis/pricing/pricing.aspx