Filter From Discount Leisure Products?

I would be very wary about buying a filter whose brand name is not given.  Looking at https://www.discountleisureproducts.co.uk/aquarium-supplies-c3/aquarium-pumps-and-filters-c6, the company names the brands of the other filters (most are well-known/reputable) but doesn't given this particular one a brand name, so I would definitely avoid it.  There's a company which sells filters - All Pond Solutions (Chinese filters, as far as I know) - and, looking at its website, the reviews all seem glowing; however, looking at reviews on a more 'neutral' and non-brand-specific website such as Amazon or e-bay reveals some scary reviews such as filters causing fires or electric shocks.  Hope that tip is helpful.

I'm not 'au fait' with external filters so someone else can advise on that but, generally, Eheim, Fluval and JBL have a good reputation. I'm also increasingly reading good reviews about OASE.

I have a JBL CristalProfi internal corner filter - it is very streamlined and addresses the issue of keeping as much out of view as possible but its major downside is that it doesn't sit neatly in against the tank walls, and kept floating out at the bottom and getting fish and my nerite snails trapped behind it. I did eventually manage to address this by buying some very strong and waterproof magnets from a specialist magnet company who were extremely helpful - the two magnets each sit inside the filter and on the outer part of the glass.

A black aquarium background wallpaper-like backing is very good for disguising black-coloured tank equipment. I converted to dark blue some time ago as I thought it showed off the fish colours better but, in hindsight, wish I hadn't for the aforementioned reason.