I think the 145l RUB bin is the best for a Syrian - the Really Useful box website sells it for about £39. It is a really good size because it's about 60cm deep as well as about 80cm long. I think the Samla bin is too small for a Syrian with syrian sized stuff in.
However as the RUB bin isn't cheap, it makes an Alaska cage a good option instead - it's about £34 from Zooplus and no diy
Although it does need a house and a wheel but then so would a bin cage.
https://www.zooplus.co.uk/shop/small...r_cages/284288