UPDATE: Well I got the car scanned a while ago and a host of errors came up. Front right wheel sensor, rear right wheel sensor rear left abs sensor and vsa activated for too long error or something like that. Hearing my mechanic say all this, I thought, wow, this is gona be expensive. I asked him to clear all the codes which he did. Restart the engine, all the errors went apart from the rear right abs sensor. So managed to source a rear right and rear left sensor. Finally got them yesterday, customs wanted £17 but anyhoo.
I fitted the sensor - rear right only - myself this morning which wasn't too bad of a job to do to be honest. I took the brake caliper, brake disc, stone guard and hub off as the sensor snapped off whilst trying to remove the old one. Ended up drilling it out in the end. Cleaned everything up and put all together. Went for a drive and the lights went out after about 10mph. So far it all seems good. I also splashed out and changed the front discs and pads - went for Pagids which look very good quality and I like the coating they put on them - and also did an oil and filter change. I still have to do the coolant change as its due now - about 18 months old current fluid, but that will keep for another day. I wish I had taken pictures to post up here but I was anxious to see if the fix had worked and it did. Will try and take some pics for coolant change with detail and post up when I get round to doing it. I would recommend anyone doing the sensor replacement to remove the hub as any damage will cost a fair bit to put right.