spotting scope suggestion for a public bird hide

I volunteer at the bird hide at Edithvale Wetlands, in suburban
Melbourne. We are looking to replace a spotting scope used by the
public under supervision. I am after suggestions from the list.

The scope would be used by novices – particularly children – to look at
waterbirds and waders in good light and at ranges up to 150m. We have
found that little kids struggle with binoculars but enjoy looking
through a solidly mounted scope. Use of the scope will be supervised by
volunteers. We will unmount and secure the scope when not in use.

I guess we need a scope, a tripod head and a mount

1. Scope

Probably an inexpensive 60 to 70mm diameter scope with an angled, zoom
eyepiece.

Bintel have a Celestron Ultima 65a w/16-48x Zoom for $259,

2. Tripod head

A simple pan/tilt tripod head. Only need two degrees of freedom and
doesn’t need quick release. A decent handle to steer with would be good.

Something like a Manfrotto 700RC2 Composite Video Head
?

3. Mount

This is where I get into trouble. I think we want a mount we can
permanently bolt to the floor, with adjustable height. A column would
be preferable to a tripod, as it is takes less floor space.

The nearest I can find is a Opticron BC-2 Hide Clamp

with Center Column. We could bolt a wooden post to the floor or perhaps
mount a bracket off the wall, then clamp the hide mount to it. This is
expensive in AU, but quite reasonable from USA. I’d prefer a steel tube
as weight isn’t an issue, but …