b,

I had to think about what would be best. You have several choices.

1. Subsurface drip which would eventually clog and need replacing every so often.
2. 1/2" pvc pipe with small narrow strip pop-up.
3. Pop-up system that throws water across the patio. These would be kept low to spread water below furniture. This irrigation would be fairly infrequent depending on the drought resistant vegetation you use. This would be the easiest to install and less disruptive to the patio paving.

Let us know what you decide. If you have more questions ask away. Aloha