You can probably build this yourself with bazzite and a compact pc, but the pricing looks pretty attractive (for the ryzen variant at least)
I dunno, isn’t £588 more than a 512GB Steam Deck would cost? That seems like the safer bet to me.
The 8600G is quite a leap ahead of the Steam Deck in terms of performance and architecture. But of course you can just take the steam deck with you and play on the go or in bed ;)
And also if your goal is just to emulate old games you might not even need the extra boost anyway!