If it were me I would add a hitch reciever to your vehicle, (you can find it here (
https://www.autoanything.com/towing/73A3874A0A0.aspx). The are super simple to install yourself, (takes about an hour with common tools), the one on the link is $150 bucks, you can probably find them cheaper elseware). Later on if you decide to get a real trailer, you will be all set.
I would then get a hitch reciever T bar, to mount the boat on, (the capacity of those are 500 lbs and securely hold your boat. The stock roof racks and most aftermarket roof racks are only good to around 125 lbs, (your boat is way over max, especially with the AMA's along), basically it's just not safe up there, I have seen dozens of kayaks torn off the roofs of vehicles, (roof racks and all), especially down here in Florida where just about everyone own a kayak or two.
You can get a tilt-able Tbar from places like Rhino, but their kind of pricy, or you can get a rigid one, (doesn't tilt down) for around $60 bucks from Amazon (
https://www.amazon.com/Erickson-07605-P ... 8B06NNFZES)
We had around 3 1/2 to 4 ft of overhang out the back of our Yukon Denali SUV's (we had 3 Denali's, and 3 TI's over the years), with around 1/4 million miles of roaming around the country with Hobies on the roof, (yea we travel a lot).
Loading with the T-bar over the back makes loading kayaks much easier, and saves damaging your roof, (we damaged many roofs severely loading and unloading kayaks)
On our latest truck (Sierra Denali) we us Thule Aero bars, they are really nice, (but a little pricy), that mount over the truck bed.
We have always hauled our boats right side up, (way less risk of damage to your car, especially with Adventure boats, (those AKA cross bars really wreck your roof, (speaking from experience here, lol).
We tried all types of kayak mounts and pads to hold the kayaks, every one of them dented the heck out of our hull, we ended up using no pads at all, and just use 1 1/2" dia wood closet poles to support the boat, (available at Home depot, (we get the ones that are PVC coated). Here is a pic of the closet poles:
Yea we have ripped off a quite a few kayak roof racks going into parking garages, so I don't keep anything permanently mounted to the vehicle. We just flip the boat up onto the roof, slide in the closet poles under the boat, then strap the boat down.
Here is a pic of one of our Yukon Denali's all loaded up, (with T-bar above) and ready to go to our other House in Key West.
Here is the front view, (notice the straps on the front, (very important):
Here is a pic of our rig last yr, (we went to 41 national parks, (we were gone 6 months):
When we have the boat on the roof for sometimes months at a time, we typically stuff pool noodles along side the boat to help even the load, (especially in the hot Florida sun).
In this pic you can see the many ratchet straps holding the boat down, when you go 15k miles for like 6 months of travel thru all weather, climbing mountain passes, and sometimes thru really bad storms, you have to have everything secured, (lol we didn't lose the boat even once). However our truck was overloaded weight wise with the camper attached, and had to put the boat in storage when we went to Yellowstone and the high mountains, then picked it up on the way back.
Good luck
FE