Major ECU problems: any help/advice appreciated!

Good Evening all,
First time poster, first foray into Nissan-land! Bought a 1.2 S K12 Nissan Micra back in April 2011... only soon to realise that it was suffering from the dreaded stretched chain-cam issues.

Cut a long story short, ECU has just packed in (diagnosed through car running on limp mode, and a working throttle body switched in to rule it out): fault codes point to blown ECU also. Question now really is what parts are needed to get her running, and is it a DIY job? I'm a competent DIY'er and happy to give it a go, as long as there's no coding involved... the main car's a VW and as happy as I am tinkering with Vagcom, I wouldn't know where to start with a Nissan.

Looking at eBay, I gather the following parts are needed: ECU,BCM MODULE,RECEIVER RING & IMMOBILISER MODULE. Does this sound about right?

I was told by one gent selling an ECU on eBay that it is possible to have the ECU fitted alone? The main reason I'm having to take the bull by the horns on this one is every single vehicle electrician in the Blackburn, Lancashire area seem to be absolute cow boys and can't seem to keep an appointment to save their lives: you'd think they were immune to the recession!

In any case, sorry for going on and any help/advice would be very gratefully appreciated!