kaitak pretty much nailed the 'actual' dates if you order through the RMK shop or dealer network...not much more to add there, but...
There are roughly 500 different configurations of RMK's, so once you decide which model/make/option you want, then go looking...
On forums like this, ebay, on-line auction houses, etc. Have a price/configuration in mind, and cash in hand...6 months of active searching and you may find it...but keep in mind, the 'deals' don't last long...usually just a few hours, so be ready to pounce when you find 'your' RMK for sale...
Or, set back for a few minutes, then start the six month search all over again...lol
As a reference point, we've been looking for 2 models for two years now...
Mel