Want to build my own equipment.

Check the net, Check the net, and once again check the net.

If you want to build amps, check out barns and nobel's online service.
I got some very good amplifier construction manuals from there, cant remember the name off the top of my dome tho.

Just go there and look for books on loudspeakers or amps, there are plenty that will give you some excellent knowledge.

It doesent really look difficult either.

Custom metal cases?
Once again i would just search the net. Look for any type of Metal Fabricators. Certain you will find something that will suit yer needs.
As far as "High end" goes, im not sure metal workers will understand what you mean by high end, but if you tell them what you want im sure they can fab it for ya, and im sure they can make it every bit as good as say, a jeff rowland amp chassis

Dont let these people get you down. You can build gear for a fraction of the price if you have even basic knowledge and some good books on the subject.

You might not be able to build the best without the right test gear, but you can make Amps that will easily surpass Adcom, and you can build speakers that sound like speakers purchased for 2-3 times the cost.

Talk to other DIY'ers, It looks like a daunting task, but all in all it is not all that complicated to make a good loudspeaker or amplifier.

Remember, even the best audio engineers and loudspeaker designers started somewhere.

Almost every audio company started out as a DIY project in somone's garage.

Just set realistic goals, accomplish them, research more, set a higher goal, and continue so on and so forth.