Wheel and platform advice needed please

[LouisB]

Hi
I have just upgraded my syrian hamster's cage to a Bucastate. She currently has one of the large plastic Trixie wheels.
I am confused about platforms and need to buy some. If I have 10 inches of substrate in the cage (which I'm just about to do), many of the platforms I see online wouldn't reach the base of the cage as they seem to be only around 15cm high. I would have thought the legs should sit on the base rather than just in the substrate. Is that right? I have seen some of the more expensive ones with options for longer legs, but not many.

Also, would it be safe to have her wheel on a platform? I can't really put it in the base of the cage as if I have high substrate, it will just get in the way of the wheel. I have tried having a higher level on one side of the cage and lower at the other, but this never seems to work as with little legs running about in it and with the effects of gravity, it all ends up as one level. Any help or advice is much appreciated!