Ties for new mine train exhibit

We are creating a new exhibit at the Campo Railroad Park & Museum. It will feature a 24 inch gauge mine train and explore California History: Railroads, Mining and Argiculture. Tghe heavest locomotive is 5000 punds over two axles.

I'm not sure if this is the appropriate forum to explore this question - if not, please suggest a different one.

I would like to keep maintenance of the 24 inch gauge tracks to a minimum. I'm considering alternatives to wooden ties. I have steel fence posts upon which I could either bolts the 10-20 pund rails or weld them. I could also lay a continiuos grade beam and bolt down rails. I could use plastic wood. Does anyone have any suggestions, alternatives, comments on any of these ideas?

Thank you.

Jim