Just to clear it up, there is absolutely no problem towing a Land Rover 90/110 with another Land Rover 90/110.
A 110 weighs around 1,900kg and a 90 about 1,700kg (kerb weights). So any trailer plated to carry that weight will be absolutely fine. Plus a vehicle that is plated to tow it, and a driver licensed to do so also.
A transporter will be less hassle if you don't have a capable tow vehicle or don't know anyone with one, however if you do then hiring a trailer is cheap and easy - so long as the requirements above are met. Any decent sized trailer will carry most Land Rovers. I have an older Ifor Williams flatbed that's plated at 2,600kg gross with an unladen weight of about 600kg - so I can put about 2 tonnes on it meaning I could move a 90 no problem, a 110 would require careful measuring as it would be closer to the limit and a 3,500kg plated trailer would likely be better suited, however mine would technically do it.