Great, but I thought your original post states you have pop - ups on the zone, so now an I correct in assuming you will be dedicationg this line for drip? Please remember these comments are read by others, so forgive my wanderings - they are attempt to make it relavent for all.
If this is dedicated just for drip, the specific set up much simplier. Since drip is really a low presssure, low flow situation, the normal irrigation concerns of presssure loss and volume sufficiency are reduced. But, any design, must consider the volume of water needed. Most inground system have ample water for an average to large sized border. So, how many and what type plants? Soil type and topography, Area of beds). I will assume you have 150 plants. I will also assume a 100 by 15 foot border. If your application is much smaller or larger, write back with the dimensions for further help.
Starting at the valve, you need a filter and a pressure reducer. Filtration is the secret of sucess in drip. Filtration, filtration, filtration. 150 mesh is adequate, unless you are planning to use miocro-spray, and then you need 200 mesh (higher the mesh number, the finer th filtration screen). Depending on emitter type and length of run, you want the pressure reducer to keep the presssure at 25 to 30 PSI max.This sites sponser has many, of both components. If you are adding this system to an area where ther is a pop-up head available, the Rainbird 1800 R (for retro) has a 200 mesh filter and 30 PSI filter reducer buit into a 4 inch pop-up body. $14 at
http://www.sprinklerwarehouse.com/Rainbird-Retrofit-Kits-s/137.htm I use these routinely. You will need to purchase a threaded "T" or "el" to go on the top, and a compreesion adapter to attach 1/2 tubing. If no pop up head is close, I install a filter and pressure reducer in line AFTER the valve, and put it below ground in a valve box. If you navigate the site above, you will find many options. I recommend any of the MPT threaded Wye filters. Rainbird makes a compact filter and pressure reducer for about $18.
Next is the emitters. I use Netafim CV 1/2 inch with inline .9 GPH emitters spaced at 1 foot. Netafim is relatively flexible (9 inch turning radius), and has check valves, so minor elevation grade changes (up to 6 feet of grade change) do not cause puddeling at the low spots. I think the above site caries Dig's rendition. I find the Toro brand to hard to snake in and out of existing beds (has about a 26 inch turning radius). I use 8 finger spray stakes (shrubblers) for containers (see my avitar), and occasionally in ground cover. They have adjustable tops and can cover up to an 18 inch radius depending on flow. They do not need the finest filtration and do quite well at 150 mesh. They are very easy to cleanout in case of clogging. I also use the 0.5 GPH drip along 1/4 inch tubing. It comes with emitter spacing every 6 or 12 inches, and is extremely flexible, for weaving in and around annuals, ground covers, and around the base of shrubs. I use it for all of the above, and particularly when 6 inch spacing is required for more even distribution around plants with shallow fibrous roots (Blueberries), or in masses of ground cover where there are multiple closely spaced plants. In my own garden, where I like to putter and change regularly, I use the single pressure compensater 1 GPH emitters.
I plan on 1 GPH per 18 inch of canopy. So, a shrub 36 inches wide, would have a drip along hose with emitters spaced at 12 inches run thru the drip zone (about 1/2 way between the edge of the canope and the trunk) and run for 20 to 30 minutes. If the plant is a high water user (Hydranga), might curve the hose under the drip line, so 3 or emitters feed it. O smaller, well established plants, I try to position the emitters so at least two will feed the existing root area. I do not worry about trees that are established, as they have generous root systems and will find the emitters. Your own run times wil be influenced by plant water needs, soil types(s), slope, plant size, and if established or not.
Although emitters may be burried, they do best when covered with a mulch or woodchips, as their is
LESS likelyhood of root intrusion.
Depending on how you design your system, you may need 1/4 inch transfer barbs, 1/2 tube closures (figure of "8" work well), and get some repair items. Remember to search fo your system before digging, or you will be amazed how your spade finds the tubing for you.
Lastly. I am not familiar with Toro valves, although they are widely used. The problem with using some valves is they will not close if the flow thru them is too slow. Check their webpage, or if you are placeing a filter and pressure reducer in ground, maybe you can just replace the valve at the same time that handles low volume closure. Since I think you are going retro, just try it, and if it does not open or close properly, you wil know the solution.
Hope that helps. A general retrofit overview. Write back with questions.
Jeff