Speaker Placement Problem

Because of space issues in a home office I must put my speakers on a large bookcase. At most, I have 3/4 foot of space behind and to the side of the speakers.

Can anyone recommend bookshelf speakers that will work in this environment? Cost is not as much an issue as the fact they must be compatible with a Manley Stingray amp.

I listen to mostly acoustic and vocal jazz and rock.

Thanks for your help.