Just for peace of my mind can I get some opinions. Take it to garage for inspection or look for new engine to take to the garage and just tell them to swap the engines
If you can do without your vehicle then you could explore various avenues but if you need it ASAP then check with the tuners if they've got anything for sale - place and advert in the wanted section on here and explore eBay.
Expect to give in the region of 1K for a used lump with limited history and further bits to fit e.g. tbelt,water pump,cam chain and oil strainer as you'll never have confidence to press the accelerator. These bits probably could be covered with your original engines salvage value.
Recovery costs will depend where you settle for it to be repaired but by the time you pay all your expenses and the VAT you'll be closer to 2K to driving it once again.
Tooling means limited DIY work and it will take you an age without past experience with this type of work.
Repair of your existing is open ended since its failure and damage hasn't be diagnosed but if your lucky that way could come in under 1K and if very lucky less than £500 but this again will be slower route as it will require finding what you need 2nd hand as new costs will be terrifying.