Predator 10k help, advise needed

Ok so I'm looking to buy a predator 10k antenna and I'm not sure which one to get. Do I need a sw dual coil or regular single coil and which length shaft do I need? Here are the measurements for my antenna mount I have placed on the back of my freightliner bulk truck. It's a mid roof. Tge distance from my mount to the top of my roof is about 25inchs.. The distance from my mount to 13'6 tall is about 70 inchs. So what setup do ya think will work the best. I have a wilson 2k mounted their now but I need to get the coils of the predator above the roof or close to it as possible but still not go above the 13'6. Please if u can help me on figuring this out I need it

 

Thx so much, I wasn't sure if the 27inch shaft would be added to the 60in or not which would be to tall. I got swrs at that mounting location to 1.2 across board which is why I want to use that location. I tryed everything the mirror perch, 9at top of hose rack on the rear and nothing worked. I was told to run a ground to air horn but this was after I found the current mounting spot. I'm going to order the 27inch shaft and comp single coil. I have a 1x4 amp I'm gonna add onto my galaxy and don't wanna fry something soon as I key up

 

I have a 2k on top of that rack already but the swr was always crazy sending warnings to my radio

 

Oh and I used the 5inch shaft with it on top of rack but I was hitting over passes up around buffalo I believe. First it took just rip off then it took the entire whip with it. Lol

 

I will need to cut a lot off the whip? I cut 1/4 off the Wilson

 

Yea that top piece wasn't grounded and I think if I can find a predator with 27in shaft competion single coil if will work great. I just measured and it will have the bottom coil couple inches over my roof and the whip will be at 13'6. But everywhere online I look says comp antenna doesn't offer 27inch