My parents also live in Clanfield and I would suggest that you also contact the Parish Council Clerk who should be able to help you with grant funding, however they do have limited funding should there be a number of street parties. They have specific powers to assist with this type of activity and should be supporting their local community.
If you require a road closure then you will need to apply for a licence from Hampshire County Council.
Also contact your ward councillor at East Hants District Council as they help provide community grants.
Also you may wish to subscribe to http://www.streetlife.com to help raise support from local residents.
I hope this helps. All the best.
Hope this helps.