Try scratch building!
Even with all the hatches open the detail seen inside is more representative that exact. Everyone has a box of spares with small goodies that can be reused for tank interiors. Think OOB and source parts from dollar store craft sections, brass crimps in various lengths are great for everything from cans of food, barrel details and even ammo brass.
If you have good reference pictures it can be built! Every resin master started out this way.
Inexpensive Tiger I?
Best deals are found at model contest vendors tables, even a partial start can be salvaged into a show stopper. This way there is no S&H fees or surprises when items are mailed. Take a few kits for trade $ to lessen the cost.