Steve,
You are correct that B&O uses a carrier frequency of 455KHz for all its modern day remotes. You say you want to integrate other brands of light controllers with your B&O system, but much of this work has already been achieved and therefore you may wish to review these options before looking to make something from scratch.
If you are looking at using Lutron light controllers whether B&O compatible or not, then there is a direct solution today with the Beo5.
With other light controllers where you wish to use a Beo4 or Beolink 1000, then I suggest you review the Lintronic IR converter box HERE
The IR command string is fairly complex compared with other brands and takes the form in Hex of
4 bits header followed by 5 bits of address then 8 bits of data and a checksum for each transmitted command.
If you have a Beo5 or plan to purchase one in the near future, then this will provide you with the best solution for controlling almost all lighting products and many others.