Yes I'll add to this that your link budget is more that adaquate.
I have shot a 5.8Ghz 18mile link with 2 27dbi dish's and 2 100mw cards.
There was more than enough signal , 48 mb connection rate, although throughput was poor because of long ack.
I have since divided the link in 2 and more than doubled the throughput.
On one end of each link I have an original 27dbi grid on the other end only a 17 dbi flat panel ant
Each of these links is +10 mile ! (the divided original shot takes a differnt path)
Throughput and reliability have been rock solid over 2 years now.
They connect at 108 mb "turbo" without fail
In storm conditions it slows down to 96 mb never lower.
The larger dish not only improves transmissin strength but reception sensitivity.
I have been able to connect and surf off a 24 dbi ant on a 60foot tower in 2.4ghz with a 18mw laptop card with no external ant at over 4 miles ! Again the the dishes sensitvity is the key.
I have found this calculater indespensible http://www.terabeam.com/support/calculations/som.php
Have fun with your link !