If your worried about tree roots then why not go with a smaller bush.
You can get different hedges and let them grow high enough to block or to make the landscaping look natural. Even think of berry bushes or ground covers to blend everything in. when i landscape around my house i make it as easy as possible. i look for plants and trees that need a minimal amount of pruning. I also look for perennials--they might need to be divided but thats a lot easier and cheaper then buying annuals every year. I have also put in bush cherry's and next year the blueberries. i have tied them into the landscaping and it makes things much easier, even when mowing around.
good luck,
dont forget your slope, and over plan for the amount of rain, water is very powerful.
forgeblast