You will have to buy a complete front differential from a 11-12 Ram to make the gear swap in the front. The guys that have done this swap have found the diff's either on E bay or a salvage yard. Once you find the front diff you still have the front and rear gears to buy and the install kits. Then if you are unable or unwilling to do the work yourself you have to pay someone to do the front swap, then set up both gear sets. Your looking at between $3000 and $3500 probably. If you do a search you will find a few threads on this type of gear swap and as I remember one of the guys listed each part you'd need along with the price he paid.
Jay