What models do we think will be suitable for this engine?

Will it be powerful enough for Graupner or Airworld Turbo Raven? What about other options?

NO1, can you explain the prices you have posted? I assume they are US prices (albeit in £) but even adding UK VAT at 17.5% the price you have posted for the 54 turboprop is cheaper than indicated on the Wren website.