Reddit mentions of Varanoid Lizards of the World

Ok, first of all, having lived in Ireland, I would recommend an indoor enclosure. Cold is one thing, but stone buildings really retain cold. It is no place to keep reptiles. Secondly, as has been expected, I would caution you away from getting a monitor lizard as a first reptile. These are difficult to care for and even advanced keepers have their problems. They require meticulous husbandry, a crazy amount of food, huge enclosures, enrichment both physical and mental, interaction and training.

They are super intelligent, think mammal or bird-like. I don't mean emotionally intelligent, but cunning, problem solving intelligence. Some, but not all, will bond with their owner in the manner that a parrot does. This takes many hours of patient work on the part of the keeper to socialize them. If you do decide to keep a monitor lizard, you will most likely have to give up traveling unless you have someone trustworthy that you can train to care for it in your stead. The reason for this is their high rate of metabolism and their activity level. They eat voraciously and require daily feedings when young and every other day as adults. They need a lot of space to move about. Some species are more active than others. The higher the activity level the more space they will need.

You should have a reptile / exotic veterinarian that is local. The responsibility of keeping a monitor lizard for the 15 -20 years of its lifespan is serious and long termed.

If you still wish to keep a monitor lizard, read some books about them before making any decisions. It is a good idea to learn about the ecology of these amazing animals. I would suggest this book as a start: https://www.amazon.com/Varanoid-Lizards-World-Eric-Pianka/dp/0253343666/ref=sr_1_1?keywords=varanoid+lizards+of+the+world&qid=1572727341&sr=8-1

If the space you can provide is limited, then I would recommend a dwarf species of monitor lizard. These all come from Australia and are only available as captive bred, so the chance of obtaining a quality animal is much greater. Varanus acanthurus (Ackie monitor / Ridge or Spiny tailed goanna) are one of the most prolific breeders in captivity and their care requirements are easier to manage. A single adult can be housed in a 5' x 2' x 3' enclosure, which you should be able to keep in your house. Their diet is primarily insect so it will be possible to develop breeding colonies of them. You could probably keep these in your shed. I don't know what the size of your shed is, but most medium to large size monitor lizard enclosures will require all or more than your shed.

Ackie monitors are inquisitive and once trust is earned daily interaction with them is possible. They can reach a full size of 20 - 30+ inches. They can live 15+ years and it is even possible to move with them as their enclosures can be carried out and loaded into a van, unlike larger enclosures which need to be broken down, transported and rebuilt. Once you are permanently in a larger, more stable house/apartment long term, then, armed with your experience keeping a dwarf species, you may be able to keep a medium-large species.

For what it's worth, that's my 2 cents.

Here are some pictures of dwarf monitor lizards:

V. acanthurus (this is an unusually large male) https://i.pinimg.com/originals/8e/9c/8d/8e9c8dd150ed3405d8a816bb80ca8695.jpg

V. glaureti https://i.pinimg.com/originals/59/05/4c/59054c3a1c605df829b21e19a256c4ec.jpg

V. gellini http://www.faunaclassifieds.com/forums/attachment.php?attachmentid=467406&stc=1&d=1365780250

V. brevicauda https://a4.pbase.com/o4/76/500676/1/55933586.brevicaudasizelowres.jpg