The only cargo door models Im aware of is the -200c Royal Nepal Airlines(1 Combi only one in existance) and the-200PF(Package Freighter as owned by UPS,20+,but no windows fitted).Ansett Worldwide have 4 PF's for lease one currently with Icelandic and one with Ethiopian.DHL has a freighter version (-200SF) with ex BA models,coverted at Boeing Witchita.Work also subcontracted to IAI(Israeil).(42 I think)The PF has slightly increased range,none are fitted for-ER.
Pemco Aeroplex in Denver offer conversion to all-cargo,combi or QC.
Pricey option for Helens Limo.
But should look kinda sexy with a pair of sidewinders(the only missile the RNZAF can afford )under the wing.Throw some accoustic gear in and it could replace the P-3.Now where's the winch going to go?A real multi role machine!!