Would a single line of drip tape or soaker line be sufficient or should I run two parallel lines? I’m not sure how wide the root system is, plus, my soil drains pretty well, so my drip lines only wet about a 5-6 inch wide area on the surface, which probably corresponds to maybe 8 to 10 inches wide once you get a couple inches down.
Yeah in anything but clay the per-dripper coverage is about 6" wide. I would do two drip tape runs offset so the emitters coverage makes a zigzag pattern. Remember that drip tape works best at low pressures (10psi?) so you might need a pressure regulator - a kit would include everything you need.
Check out https://www.dripdepot.com/
If you are referring to caneberries, irrigate at least one foot each side of row center.