Basic, Decent Stereo Audio for Netflix/DVDs

[Zig13]

Looking to replace my dying Aiwa XR-EM20 (90/00s HiFi minisystem) in it's function as layman-good PC speakers for my partner's PC when we watch Netflix/DVDs. Neither of us are audiophiles and we're not interested in surround-sound.
We've been perfectly happy with the sound quality of the XR-EM20 but it cuts out and the LCD display is stuck/dim.
Looking to spend sub-£100 on some kind of amplifier and ideally keep existing 6 Ohm speakers to be replaced/upgraded later. Don't really care about tape/CD/radio but would be nice to be able to add them on later.
Focus is on longevity/stability over sound quality.

Inspired by Techmoan's series on a Beginner Budget Hifi Build, I've been looking at 80s/90s Recievers and Cassievers on eBay. A KENWOOD AX-31 Cassiever at £50 has caught my eye but I've also seen a Technics SA-K2L as a even cheaper option at £20 although it has one fewer input. The problem is with such pre-internet products you can't exactly look at reviews :/ .

The plan would be to pair such an amplifier with an affordable DAC with 3 optical inputs connected to it's Aux. That way the amp/speakers can be connected to my partner's PC (and 30-inch Apple Cinema HD display) for DVDs/Netflix but also a Chromecast Audio and my PC for my music collection.
A priority would therefore be a lack of hum as the amp would be kept on 24/7 connected to the chromecast audio.

What do you think? Am I crazy? Is there a better way of achieving the same effect? Am I being a bit too stingy? What's the advantage of the expensive, branded DACs over the numerous cheap ones? Is it a really bad idea to use 6 Ohm speakers with an 8-16 Ohm rated amp - even in the short term?

Thanks!

 

[Zig13]

That's a very clear, detailed explanation thank you very much! I feel like I have learned things

The speaker impedance question depends on how loud you need the system to go

Neither my partner not I like things loud. When watching a film we have it just loud enough for dialogue to be clearly audible. Not that it really means much, but we usually settle on a volume of 21/29 on the Aiwa and it's rated at only 65W!

There's a good example of this on Ebay right now. It's a Cambridge Audio A500 (Ebay item no# 264094808488). Depending on whether it's a v1 or v2 then the power rating is 50W- or 65W per channel. From the listing's pictures you can read the back panel power consumption as 400W.

That's a real deal! Unfortunately it's collection-only which probably explains the lack of interest.

The Kenwood I saw is rated at 90W
The Technics I saw is rated at 120W

What are the British Hi-Fi brands to look out for? Obviously Cambridge Audio but who else?