If you're buying a bluray player, I wouldn't bother with an all-in-one system with built-in DVD player. After all, you won't use the DVD side. Bluray is capable of outputting HD (lossless) audio over HDMI. These cost consdierably more than the £90 system at Aldi e.g Sony systems at £320. I will not go into why I would not buy it. You're on an AV Forum, so you should be able to guess!

but whatever you buy should have a digital audio input so you can get discrete multi-channel surround sound. Basically look for optical and digitcal-coax inputs as a minimum. This won't get you HD lossless audio as these connections lack the necessary bandwidth but will be 90% of the way there. If your proposed system has analogue audio inputs (it may well lack inputs full stop) all you will get is a pseudo effect, which is not true surround sound. Up to you mate, but I would stick to buying groceries only from Aldi
PS Welcom to the forum. Using capitals (CAPS) is considered shouting by the way.
Edit - Everyone seems to want wireless rear speakers but they're never truly wireless as they need power. You can get discrete cable or conduit for hiding cable eg. dline