If you goggle "section 8 notice" you get one or two free sites
In the end I bought a book - Landlord and tenant or something and they are in the back (usually)
Since this is clearly a first
for end of lease wh I think is s 21 - you have to put in the day the lease ends and not the day you want possession - this is a must
and for s 8 wh I think is rent arrears - when you come to make a statement of claim you must put in somewhere I am seeking repossession for rent arrears that is ground 8
http://www.landlordzone.co.uk/forums/showthread.php?15741-Housing-Act-1988-wording-of-grounds-8-10-and-11
goggle ground 8 and not section 8