Question : Problem: Commercial Wireless Antena being driven by d-link home router. Is this okay?

I have a potential new client that has the following setup and problems:

setup:
1) They have a home based D-Link DWL(something) that is running a no-name commercial outdoor antenna that is roughly 2' by 2' and is rectangular in shape.
2) They are trying to get the signal to a building that is roughly 100 yards or more away from the antenna, but it is line of sight with no obstructions where they hope to hardwire the building with the signal coming into the building from the wireless antenna as well placing signal boosters to allow wireless connection throughout the building

problems:
1) They are not able to get a reliable signal to the building that is roughly 100 yards or more away. They get intermittent signal drops and unreliable connectivity.
2) Even directly outside the building with the antenna, they only get two or three bars from a 5 bar reading.

Questions:
1) (200 points) Is it likely that a home based D-Link DWL(something or rather) router can drive a commercial outdoor antenna as described above?  
2) (100 points) Do most commercial antennas of this size need a particular amount of power to run them? My understanding is that the maximum transmit power for a public band signal like this is 1Amp.  Is this right?  If so, what kind of reasonable priced router would run an antenna like this?
3) (200 points) Are there distance limitations, repeater limitations, etc. similar to copper based Ethernet that need to be followed?  i.e. is 100 yards too far for a wireless signal to transmit a signal reliably and will they then be able to repeat or boost the signal at a fairly distant location like this?  If so, how can you overcome these limitations or do you have to use different technology to cover this type of distance.

I'm posting 200 points initially, but will add points if all questions are answered or if I feel the answers on any particular question outweigh my listed point value.

Thanks,

Jeffery Smith

Answer : Problem: Commercial Wireless Antena being driven by d-link home router. Is this okay?

This is what I do:

You need 3 Wireless Acces Points to do this and the DLink Router:

Building 1:
DLink Router Providing Wireless to Clients in Building 1
Dedicated WAP for a Bridge Connection configured on an isolated secure SSID as a WAP with a High Gain external antenna. Connected to the network via the LAN port.

Building 2:
Dedicated WAP for a Bridge Connection configured on an isolated secure SSID(same as SSID on dedicated WAP from building 1) as a Bridge with a High Gain external antenna.
Separate WAP to serve wireless clients in building 2.  The Bridged WAP gets connected to a switch along with the regular WAP to allow the Wireless Router to provide DHCP and other services to Building 2.

A wireless bridge will give full speed wireless.

.....:)