art,

I would go with drip tubing whatever spacing you like with a pvc pipe mainline and small manifold to spread out mainline and be the start of each row. One main shutoff with vacuum breaker backflow preventer, one in-line filter if not house water and one pressure reducer for what the drip lines are rated. There many kits sold from most Big Box, plant stores.
What will be your pressure and flow rate? Aloha

Do you have experience with either of these?

http://www.google.com/products/catalog?hl=en&biw=1280&bih=610&q=raindrip+drip+a+long&um=1&ie=UTF-8&cid=552940744194508247&sa=X&ei=11i_TaO2FqTYiAKelr2xAw&ved=0CEcQ8wIwBA#

http://www.amazon.com/Gilmour-Weeper-8-Inch-50-Foot-27-58050/dp/B00004RA2V

I agree with lehua. Drip watering is a great way to go.

Here is a link that might be useful: drip irrigation

art,

Seems like you want to go with soaker hoses. Soaker hoses don't have a predictable flow rate. One part of the bed will get more water than the other. Pressure regulated emitters in hoses will clog no matter what they promise. The pressure equalizer is a torture track pathway for the water to escape the hose. Fine particles of sand or algae growth or anything tiny that can crawl into the emitter while it is off will clog it when pressure is reapplied. If your water is from the local water company the hose should be fine for a season, hopefully. Try it and let everyone here know how it went. GL Aloha