Ta, thanks Mr Withered, chuffed with it. Yep, I ordered the 2 step risers from an online retailer in Quebec! Shipping was more than the actual cost of the parts but so worth it (IMO). They looked like this before 'adaptation' to fit the job. Made the job a lot easier in the end.
As requested, finished it today, lorra lorra work but yummerz (IMO). 1st time I've ever done a sunken door mat too, very pleased with it all.