Get a quote from MORryde, then use it to work a deal with your Dealer. Remember, even without the IS you will still be paying for two axles under your unit. Use that info to try and get a little lower price on Factory installed IS vs MORryde. Either way the install will still be done by MORryde, it will just save you two days at MORryde while they do the install.
Been there, done that several times.