hey, welcome. HF only offers a 4X8 frame, so doing a 5X10 means some overhang. I'd recommend you look at the NT 5 X 8. I used one of these 3 years ago to do my 5X10X5 teardrop. I stretched the frame one foot and added 6 inches overhang to the front and rear. worked out well.
good luck.
frenchy
Five cords of wood in, snow tires on, 5 X 8 NT frame on order. Gonna build a TD this winter.