Large gerbilarium or fish tank (South Norwood SE25)

Hi all, I would like to adopt two gerbils who will really need a large tank for animal welfare - to ensure they have as happy and healthy life as possible. I'm looking for something 100 x 50+ and it needs to be a solid surface all the way round (not bars). Wire mesh or a toppper is a bonus, but if this isn't included I'll handmake this. I've included pic of the sort of thing I'm after but this isn't prescriptive.

Thanks for looking at this post!