I actually built a jib crane to load our TI onto the top of our Yukon Denali after pulling some muscles in my back. I ended up only using it twice, then gave up on it (it was much easier and faster to just hoist the boat up manually.
I have one of those t bar hitch mounts ( I really recommend them).
What I did was remove the t off the top, put some 2 inch galvanized pipe in the end with an elbow and a four ft length of pipe sticking out horizontally. I had to brace the elbow with an alum bracket. I then put a pulley on the elbow and on the end so I could run the boat winch cable up and overhead. We would hoist the revo up first on the right side, then the TI on the left side, after loading on the roof I would strap the AMA's on top of the TI (independent of the roof rack straps).
I'm not a big guy at all and am in my 60's and feel it is much easier to load on the roof than our oasis ever was ( we traded our oasis in for the TI, actually I injured my back loading the Oasis on the roof (not the TI)).
We are campers (like Atango ) and when we have the camper or when we go to our Key West house (no garage and no place to store a trailer) we have to rooftop instead of using the boat trailer.
Actually there is a quick and easy way to load a TI onto the roof, ( I think roadrunner posted how to do it easily), you are never lifting any more than 50 lbs. What I do is put the scupper cart in and walk the boat up to the center behind the car, I place an old carpet under the back of the boat, I then walk the bow up next to and along side the car about even with the rear tire. I then lift the bow up and onto my head then walk hand over hand under the boat until it is high enough to lay on the T-bar. I then center the bow ( I have a couple safety brackets that I attach to the T-bar to prevent the boat from sliding off the side of the T-bar. I then walk behind the boat, lift the back and slide the boat forward onto the T-bar and roof racks of the Denali. I usually just place a pool noodle on the roof near the back and the TI rolls nicely on the pool noodle. On short trips I just strap the TI down to the roof racks and the T-bar (the T-bar is rated at 500 lbs and supports the majority of the weight). We don't do anything else on short trips, on long trips or if we plan to have the kayak up there for more than a week or two (they are sometimes up there all summer), I typically put pool noodles along the sides before strapping down (to even out the load), and also add a V strap on the bow (to each kayak) to keep them from blowing sideways on the highway. We literally have a couple hundred thousand miles on our vehicles (we are on our 3rd Denali now) hauling kayaks all over the country. All my 3 sails fit into the Hobie sail bag, and it is slid in next to the TI. It's quick and fast (about 2 minutes to get the kayaks on or off the roof (rigging that jib crane and loading the boats using that took about 30 minutes, that's why I abandoned it)) and I always load the boats myself every single weekend (sometimes 2-3 times per weekend, and when down in Key West I load and unload daily) all year round, we've been doing this since 2006.
During the last year when local in Sarasota, I typically just use my Harbor Freight trailer ($140 bucks at Harbor freight) and store the boat fully rigged in the garage. I just hook it up, go out sailing, come home rinse it off and store it all rigged in the garage (takes all of ten minutes), in my opinion that's the way to go if you can (a trailer). It's the hour of getting all the pieces out of the car and setting up the TI (putting the AKA bars in, the AMA's on, lacing the tramps, putting the seats in, unpacking the sails, getting all the gear stowed, that is all very time consuming when car topping, which as Atango points out is the downside to car topping.
Another point I want to make about car topping is the toll it places on your vehicle when you kayak in salt water. We rusted out the roof on our denali and had to have it replaced, car topping our kayaks from salt water (we mostly do salt water these days (now living in south florida and the keys), when we lived up north and traveled, where we were doing mostly fresh water we never had a problem (just a word of warning...).
Hope this helps
Here is a pic of our rig all ready to go down to our Key West place (about 300 miles), notice the Tbar on the back I got our from Amazon for about $80 bucks, one of our best purchases ever. (that's my wife's pride and joy beach cruiser bike on the back)