Low Voltage includes Coax cable, CAT5e cable (or CAT6), HDMI, Speaker wire, Security Wiring, Smoke alarms (powered and connected, and seperate ones for security system), and Carbon Monoxide detector. I also did HDMI cabling in the walls. Phone - use CAT5e, every bedroom (this might be code) and everywhere else you want it. Internet - not as important with wireless routers, but if your house is spread out or has plaster walls, consider having some CAT5e runs to accomodate wireless access points, which are basically repeaters for a wireless router to extend range. Make sure there is a CAT5e ran to where you want your wireless router. Satellite/Cable/TV - Coax runs from the source (cable or dish) into a distribution box (for satellite, get 4 lines ran). And from there you can distribute to the boxes by coax or you can have the boxes in a remote location and run HDMI to the TV. Then you'll need Infrared Repeaters running from the TV back to the box. CAT5e works for that. HDMI over 50ft needs a repeater, they make wall jack ones. Speakers - you need to decide what type of control unit you'll have. You can run speaker wire from the speaker to a wall volume control, and then to an amp somewhere. We chose a system that used speaker wire home run to the control unit and CAT5e from wall controls back to the control unit. You plug all the sources into the control unit, and the speaker and CAT5e wire. It has a built in IR Repeater system so you can use a remote to control the sources from any room. Ours is by BreatheAudio. Have a security system do the security wiring, we opted to include a cell service attached to it, carbon monoxide detector and key fobs to turn it on and off. We have Coax and CAT5e (one internet and one phone) into every bedroom. CAT5e phone in the kitchen. CAT5e to a bookcase/cabinet for the wireless router. HDMI and CAT5e from remote locations to the Master Bedroom, Bathroom, Laundry Room, Great Room, Keeping Room and Guest Suite (so the flat panels don't have a box hanging out by them). Speakers in Kitchen, keeping room, great room, guest suite, dining room, master bedroom, master bathroom, laundry room, basement living room, workout room, wine tasting room and outside deck. Each has a control panel. We have door contacts and motion detectors for security system. If you want to know about our home theater setup, I can detail all of that for you too.

Hi - We went with Seagull under-cabinet lighting too. I got a copy of their "Ambience" catalog from our local lighting store. It gave a lot of information, but I finally realized that because of issues like those that bignick mentioned, the subject was too tricky for me to be sure I was doing it right. I contacted the local Seagull sales rep (you can probably get the rep's name from your local Seagull dealer), and he very kindly drew up exactly the layout and parts we needed. It was great! The biggest surprise was that the lady at the lighting store who was initially "relaying" what the rep said was completely wrong. I'm so glad we got the expert involved! Also, our electrician had a question while he was installing the wire, and he was able to call the rep directly, which helped too. Good luck! Ours isn't completely installed yet, so I can't report on the end results, but I have high hopes. :-)

I have the Sea Gull Linear lighting in my kitchen. In my opinion, the more finished look of the Juno isn't very important. It's not something you're going to see unless you stick your head under the cabinet and crane your neck. I like the flexibility of the Linear lighting. While I'm not familiar with the features of the Juno track, I can't imagine that it would any more versatile than the Linear cable, which not only can curve, but can also be cut to any required length. It also allows you to place lamps along the cable at any interval that you choose, and there are a number of different lamping options. Mine are 10W xenon at 6" intervals. They provide ample illumination, are dimmable and don't throw off any noticeable heat.. Here's a photo of a section of my installation:

The transformer should be in an accessible location. There should be a switch between the 120V line and the transformer. You really don't want to have the transformer being fed electricity all the time. Using the transformer as a junction box is not the best idea. In other words, probably no.