Agree with clarem, get a widgey!! They're fabulous!
If you've got big boobs you'll prob be ok without a pillow, cause bubs can just rest on your lap. However, if you're not blessed in that department (like me!) it really hurts your back trying to hold bubs up high enough to breastfeed. Widgeys are great because they're really firm and support the baby very well so you can relax.
K.xx