Growing a cedar hedge under old cedars

I have a row of five huge (about 100 foot tall) cedars along my back fence. The lower branches have become rather unsightly so I'd like to prune away the branches up to a height of about 30 feet and then plant a hedge of cedars, yew or some other type of tree between them.

Will this work or can you recommend a type of hedge that would do well under the old cedars.

 

I've got a very similar situation and I'm still (after a couple of years) working on ways to cope with it. From what I've read and been told, yews are a leading candidate because they will tolerate the shade beneath the older trees without becoming leggy or bare in spots. But yew are attractive to deer in these parts, so I've mostly planted a mixture of baby cedar seedlings dug up from elsewhere on the property, along with hemlock seedlings from a friend's place. All seem to be doing well, but are very slow-growing, especially the hemlock.

If you find any good solutions, please share them!