LC5F I have got a quote from a company online for a rebuilt engine fitted for 2K locally. It sounds too good to be true to me?
I am leaning to calling AKS tuning to see if I can figure something out tommorow as the seem to be universally recommended.
The German link has new pistons and a clever balance shaft delete set up - that's probably £1k of the price there alone.
You need to confirm what they are going to do - ask them what is being replaced new, what used items will be retained and what serviceable items they will use (belts/chains) -lastly what sort of warranty they provide.
Also see if there is any online feedback on them - don't rush into anything.
It does sound cheap - I suffered cam belt slip late last year, I did it as cheap as I could for: head rebuild, injector clean, gaskets, fixings & a DIY turbo rebuild all came in just over £1k, for the extra £1k they need to rebuild the bottom end and make a profit.
Yes AKS do seem to be very good, I would ask their advice - they will know who is trusted engine builder - more money, but I would be tempted to get balance shaft assembly delete from AKS.