Distributed Wireless Battery-powered LED Display (Arduino Newbie Questions)

I am new to Arduino and seeking a jump-start for a small project.

The project will consist of a control node and 2 or more wireless receiver nodes. The control node will communicate on/off and discrete level data for 10-200 simultaneous signals in the receiver nodes. Signals will be interpreted at approximately 30hz. The signals will drive LEDs. The receiver nodes will have line-of-sight to the control node at a distance of 50-100 feet (15-30 meters). Ambient light sensors will be incorporated to automate LED output levels.

No error correction or data security is required. Low power consumption, low latency (responsiveness), and low cost are important. All nodes will be powered by batteries. The control node will have ample battery power. The receiver nodes will have light-weight batteries with limited capacity. These batteries may have solar recharging. The system should be capable of operating for at least 7 days without recharge.

I will be programming from a PC. Ultimately, uploading programs wirelessly will become convenient.

Q: What Arduino model will best suit the control unit? Q: What wireless solution (e.g. XBee, Bluetooth) fits best? Q: What batteries best match the Arduino? Q: What is (minimally) needed to translate control signals and LED display in the receiver nodes?

TIA

Any arduino can be used for controls. The xbee or BT can connect to one device at a time so maybe not, plus 15m is a bit far for what these two were designed for. What I will do is to buy 3 cheap $10 remote control cars, take the battery (good charge) and the receiver and use that mechanism on the LED to turn on the LED (if all you want it on/off). Arduino will use one of the remotes to send signals to these receivers. I think with a typical remote, there are left, right, forward, backward. So if each LED responds to one of these above signal alone, you get up to 4 LEDs wirelessly controlled. Plus most remotes have 3 channels ;) but you will have to destroy some nice toys (on the other hand, you get to use their rechargeable batteries and keep some mechanical parts for other projects.) What can the LED do? Dim or just on/off?

How many LEDs on the receive end?

What does this mean?

"on/off and discrete level data for 10-200 simultaneous signals in the receiver nodes."

Thanks for the suggestions, liudr. I like your harvesting approach.

liudr:
The xbee or BT can connect to one device at a time so maybe not, plus 15m is a bit far for what these two were designed for.

My understanding is that both the XBee and BT are broadcast protocols. Several discussions indicate that at least the XBee Pro has sufficient range. (http://forums.parallax.com/showthread.php?133780-xbee-range)

liudr:
What can the LED do? Dim or just on/off?

There is a display of multiple LEDs; all of which dim.

CrossRoads: How many LEDs on the receive end?

Each receiver will display between 10 and 200 LEDs.

CrossRoads: What does this mean?

"on/off and discrete level data for 10-200 simultaneous signals in the receiver nodes."

Each wireless data packet must deliver independent level data for each LED at a frequency of approx. 30hz.

liudr: The xbee or BT can connect to one device at a time so maybe not, plus 15m is a bit far for what these two were designed for.

The XBee specs: •Networking topology: Point-to-point, point-to-multipoint, & peer-to-peer

Performance: XBee •Indoor/Urban range: Up to 100 ft (30 m)

Performance: XBee-PRO •Indoor/Urban range: Up to 300 ft (90 m)