Financially, you were very wise to pass on the Shelby. The Tuscany Shelby [trucks] are not recognized as regular production vehicles and as such don't have a blue book value. Their book value is that of the base vehicle that Tuscany receives from Ford. (in this case, a base model Raptor) When you go to trade, or sell the truck, the book value will be based on a standard Raptor. Shelbys that are manufactured by Tuscany are very hard to resell used. Ask me how I know...
My (mint condition) 2018 Shelby F150 V8 (755 hp) was very hard to sell when I got rid of it. Everyone wanted it but the bank would only loan $48K on it as it was considered a stock Lariat F150 by the banks. (1 year old, 8,000 miles, mint condition)
Here's the catch, the bank WILL happily loan you the $120k for these trucks at the dealership, as banks recognize the Ford window stickers that dealerships put on them as accurate current pricing. Once they're sold [as new] at the dealership, that rule no longer applies.
BTW, I loved the Shelby... That Coyote V8 with the Whipple supercharger made me smile every time I hit the "Start" button. Unfortunately, they were expensive smiles...
I highly question how long those stock 10 speeds are going to last behind all that horsepower, and abuse that generally comes with it.