Alright Steve, hope things are going well. Don't want to put a dampner on this but if the flats are used this would be a nightmare of a job. Done one in chiswick a few years back, had to start at 12/1am and still there were people coming and going and to top that someone was shot and killed in the flats the previous week cause of some drugs deal. No way did it have enough time to seal it properly without foot prints appearing on landings and stairs. As for products would go low cost with this, i used carefree speed stripper and carefree polish.
Mark.