You can still buy LS3/5a's that are modelled after original versions, but have a strong familiar sound but use updated drivers.
Check Stirling Broadcast for their LS3/5a V2 model, and they also make some kits to build a sound alike version out of Monacor drivers for a bit less. They also supply beautiful cabinets built to LS3/5a specifications and repair / refurbishment parts.
http://www.stirlingbroadcast.net/
http://www.stirlingbroadcast.net/ls35a.html
http://www.stirlingbroadcast.net/Repairs.html
Similarly, Falcon Acoustics also supplies parts and kits to build LS3/5a that are very close to the real thing. They are also making limited supplies of the original KEF B110 SP1003 because the original designer, Malcolm Jones, was the original owner of Falcon and is a consultant for them now.
http://www.falconacoustics.co.uk/ls3-5a.html
In addition, Rogers is making a BBC licensed version from internationally sourced parts (Rogers is owned by a Chinese company now) but it was designed, specified and voiced by British designers and people very familiar with the LS3/5a so you can still get them new.
IMO, other companies with little or no pedigree (GINI, Audiospace, etc) make small LS3/5a like speakers, and even use the model designation but without any license so, IMO, are poor imitations. They may sound good, but they are NOT true LS3/5a's in the strictest sense.
As above, Spendor, Harbeth, even now KEF (with their LS50) create some very compelling small speakers if that is what is needed.
Used LS3/5a's are fairly abundant in the UK and can still be found frequently, sometimes at great discount, sometimes at market price, depending on condition, maker, veneer, and many times, luck.
I've still been able to find LS3/5a's all around the world, and sometimes can still find them for less than what they sell for on Ebay, occasionally much less. Keep looking if that's what's wanted, the UK has a lot of them out there, especially with the recent closure of the Main BBC research and development center last year.