Lost Keys, 2005 TD4

Hi all,
We've lost the only set of keys/alarm fob we had for our 2005 TD4. There's no realistic possibility of finding them, so we'll have to arrange for replacements. An added complication is that we had imported the car to Ireland recently, and its sitting stuck in Cork Airport parking, racking up charges.
Now, I know this wont be cheap, but what is the best and cheapest way to replace the key, transponder and alarm remote? I've made a few cursory enquiries with a couple of specialist car key companies, all have said that due to the age of the car any replacements will need to be sourced through LR.
From my understanding, the process will involve having the car recovered and taken to the Dealers, a new key and transponder to be ordered using the VIN and the alarm to be reprogrammed. Does this sound correct, or am I missing something? Also, does all this have to be done through LR or are there any ways I can avoid their ridiculously high costs?
Any help and advice would be much appreciated.
Thanks.

In my opinion easiest is to get an ecu kit and replace ecu, driver door key, tailgate, fuel cap and steering wheel one.
Example: https://www.ebay.co.uk/itm/Land-Rov...038603?hash=item2ad306670b:g:IYUAAOSwwRtdYYID

Hi Websun,
Thanks very much for that. Although that one wasn't completely compatible, I've now found one on there that is. I'm just waiting for a mechanic I know to get back to me regarding the swapping over of the components and I could well be good to go.
Your suggestion is very much appreciated. Thanks.

Make sure you have all parts and nothing is missing especially the fuel one for example.

I've spoken to the Breakers and they have told me that all parts are included. Thanks again.

Would be worried about doing all that work in a car park!! Also, I am sure the alarm module needs to be changed too and that must match the ecu. Could be worth getting price for LR key and reprogramming. The alarm module is fairly well hidden behind the dashboard, not a job for the faint hearted!!