Ending a tenancy

Possession - Section 8 and Section 21

I have been a landlord for about 11 years and have not yet had to end a tenancy (except where a tenant gave me notice to quit) so I have no experience in ending a tenancy ( I do plan to take the NRLA short course on this). I plan to sell a property very soon into the 2005-06 tax year, Say April 2025. If section 21 still exists at that time I expect I will use that method otherwise I will have to use section 8. Could my fellow members give some pointers please.

Is section 21 or section 8 the better method & why.?

General dissadvantages/advantages of section 8 method

Ive often thought that two months notice is a very short notice period for a tenant to find another suitable property and prepare to move out especially with todays market conditions, so I am considering giving maybe a 4 month notice perid. What are the advantages/dissadvantages/pitfalls of giving a longer notice period if any?I think the main advantage is that the tenant has longer to plan and therefore has more opportunity to find a new house and will feel less resentful, therefore less likely to 'dig their heels in' and string out the eviction.

Thank you