I recommend renting or hiring the furniture as you need it. This gives you more choices regarding styles, as not every event will have the same theme or style. Also, with rental, all the stuff gets dropped off to you and picked up when the time comes; this means there is no need to store all that furniture.
Regarding places to hire from, some great companies offer event furniture hire in London. One company that I like the look of is Velvet Living. They have a great selection of styles and furniture ranges and are affordable overall. I recommend you look into that company for event furniture hire in London. Unless you throw events weekly, hiring works out better.
Hiring furniture tends to be a more cost-effective choice, and getting access to new stuff for every event means you avoid your events looking stale or the same as last time.
