I am seeking ideas how to carry 8x10 Toyo.

It's not the weight, it's the size.
I am not planning to go hiking with that camera, but I need to carry to the normal photographing locations - which means always a walk of some kilometers at least. Mostly on good pavement, gravel roads or easy trails.

The usual camera backbacks are too small and the larger are pricy too. My largest is Lowepro Pro-trekker and it's small.

The camera (when collapsed as small as it's reasonable) needs circa 45 x 50 cm x 30 cm (18" x 20" x 12") space. The latter is thickness and it's that much only at the bottom of the frames where the short rail is. Otherwise it's 7 cm thinner, requiring 23 cm (9").

Along with the camera comes the rail, couple of lenses, two film backs (they're heavy), wooden tripod and normal LF stuff (lightmeter, ....)

I have been looking some cheap, second hand army backback, but they seems to be too small.

So far.. The only solution I have found is to buy old backpack with a frame (or plain frame) and either build kind a box for camera and attach it to the frame or seek for a some large bag and attach it to the frame.

I guess that this is a problem that many of LF photographers have faced, so better solution exists, I presume.