Probably the best choice of weapon and tool would be the WWII. It is also stated on the website(shopping site) that it is the best combition of weapon and tool. The WWII comes in 2 sizes, 16.5" and 18". I have two 18" WWII's, one with a bone handle and the other with wood. I would reccomend getting one with a wood handle, it will have more grip than the bone. I have used the bone handled WWII in the rain and it was getting a little slippery, I might rough up the handle a bit. Last month there was a khukuri convention that Uncle Bill put on in Reno that I attented. One of the attendees put on a Martial Arts demo with the Khukuri. The man is a high ranking instructor of Bando. His favored weapon is an 18" WWII with a wood handle. He was saying to think of motor oil(relating it to blood) on the handle and what would grip better, wood grips better. It was very impressive to watch him use the weapon and he was very knowledgeable. Uncle Bill Video taped the Convention and got Dr. Winborne's Demo on tape. I think his martial arts demo was about 1.5 hours. I learned a lot and have incorperated the Khukuri into my own Martail Arts training. I think Bill is still making copies if you are interested. I think I paid $15 shipped for the tape.
The 18" WWII is my second favorite khukuri, right after the Chiruwa. I took my wood handled out to test on a dead tree. The tree was about 8"-10" thick. It took a bit to get through it, that wood was Hard. Did a little prying after that. I cleaned it up after I was done. It Looked like I did not even use it and it was still very sharp.
As I said before, check the HI website on bladeforums. They are building a new khukuri factory in Nepal. Uncle Bill is putting up a lot of deals to pay for the construction. They are being called Crazy Pala Deals(CPD). Uncle Bill has sold 2-3 18" WWII's in the last few days. 2 were $85 shipped, and the one left over from yesterday went for $75 shipped today, that is half price. I have bought many of my khukuris by watching the deals. They usually happen sometime in the morning. I hope this info helps. Logan