You could also do worse than try out the Spendor S3/5R speakers (£750) if it proves impossible to source the components you need. (Or look for their second-hand predecessors on ebay).
The
Arcaydis SM35Cs are made in the spirit of the originals too. (Including being made of birch ply.)
Forget buying original BBC LS3/5As on ebay. Tidy pairs can go for £1500+ and even scrappy looking ones go for a small fortune.
That BBC paper you linked is authored by H.D. (Dudley) Harwood. He left the BBC and founded Harbeth with his wife Elizabeth.
Spencer Hughes - also a researcher with the BBC - left them and founded Spendor. (Named after himself and his wife Dorothy.)
Both companies held two of the original, BBC issued, LS3/5A licences (not suprisingly) along with KEF, Goodmans, Chartwell, Rogers, Richard Allan and others.
This 'tradition' of high hitting mini-monitors from ex-BBC folk continues with
Leema Acoustics (founded by two ex-BBC engineers
Lee Taylor and
Mallory Nicholls) and their Xero speakers.
Must be something in the BBC tea.
(Some
more history courtesy of Harbeth.)