Reputable engine builders
I would have no problem recommending any of the engine builders mentioned above, I have had dealings with all of them and no problems with any of them that they were not prepared to resolve.
Engines are sometimes troublesome and in my opinion it is when things don't go as you would like you find out who will back there product.
It is very seldom that I have had to go back to any of these company's with a problem but both Eisenburg and NMA have done all in there power to resolve problems with their products, I have not had a lot of dealings with Neal Andrews or Novic so can't say too much apart from that their after sales back up is good.
Any other engine builders in the UK are not worth dealing with, they offer a good price but that usually reflects the quality of the product !