Firstly, as Patrick says, stop putting out sugar water, you'll attract any bees and wasps in the area.
Secondly, if you are not a beekeeper already then please sign-up with a local Association to learn the craft of beekeeping before acquiring honeybees from any source.
The bees you have seen may have been scout bees, which can show an interest for several days. A swarm may then appear or the scout bees may decide somewhere else is better. Or they may just have decided that the water near the boxes is the 'best in town'. The weather is atrocious at the moment so unlikely a swarm will appear, but if it does and you do not have the correct equipment and knowledge to house a swarm, then please look up the BBKA website to find a local beekeeper on the Swarm list.
Honey bees are livestock. The question I always ask people is "would you buy and keep a cow in your garden without knowing how to look after it?".