We've had a measure and to just do under the tables it's 25m of strip, with a current draw of 45A. The best source I've been able to find for addressable RGB strip so far is this one from AliExpress -
We have £100 set aside for the project, so can afford some extra strip which Laurence and I reckon would look cool going around the outside of the soundproofing boards on the far wall, which adds another 15M of strip, taking us to 72A.
Power supplies from
at £12.45/30A gives us £37.35 PSUs, £62 LEDs which gives us £100 which is close enough.
If anyone has found any better suppliers, that'd be great!
Had a bit of a play whilst soldering up some strips for Laurence's house this afternoon, it looks really cool: