Any fishkeepers in here? Looking for good suppliers online

CurlySue2017

I wasn't sure which section to post this in but pets seemed to be the most appropriate place.

We need to upgrade our current aquarium to a (much) larger one and have been looking around online, the main places that keep popping up are Charterhouse Aquatics and Swell UK, so I wondered if anyone has any experience with either of these companies?  Their prices are good but the reviews seem to be quite mixed so it is hard to tell and as this will be a big, fragile, expensive item we really want things to go smoothly should we have any problems.

Any experience anyone has with these companies (or any others that you would recommend) would be great, just to help us make a decision.

Thank you.