Bottom outlet toilet pan

[Flushed away]

Hi this is my 1st post here. Have looked in archives but not found exact answer. 1930's downstairs toilet with low flush, plastic cistern and connecting pipe. Would like to change to close coupled toilet. Have found Twyfords Alcona bottom outlet but no one has one to view. Has anyone had experience fitting one of these ?
Spoke to Twyfords but not too helpful, said its a continental unit and hardly used over here.
Centre line is 205mm from wall which is exactly same as Alcona. I need to know how easy it is to remove the raised collar around the existing outlet without breaking the pipe. Can it be left flush to the floor to take a std short pan coupler, or will it need digging down. I think from the data sheet the outlet pipe is just above floor level. Is the width of the base enough to accommodate the coupler. Do you agree this is the best solution rather than building out behind the cistern of a horizontal outlet pan with an angled coupler.
Also would the water connection to this cistern be straightforward as its classed as continental? I assume it comes in at the bottom ?

Any advice would be appreciated.

PS tried to attach pic but says i do not have permission.

thanks,

 

[JusKel]

The collars are usually sealed with lead or putty.
You could ended up having to break it out.
You'll know then what your up against.