In the UK, Trichocereus are quite popular due to their hardiness and can handle our low temp during winter (around 5C before bringing them inside, although, adults can go lower). Flowers produce after around 8 to 10 years of growth, so, patience is required.
All our cacti are shipped bare root to protect the cacti, please ensure you have suitable substrate and a pot for your new dude. If you are stuck on what to use as a substrate, we have a very handy guide here. As always, please do not hesitate to get in touch, I will help you with any questions you might have.
We have a trichocereus care sheet that you can reference.