What power transistors are there that support high voltage and adequate current?

I am looking for particular transistors that have especially high DC voltage handling capability. When I say "high", I mean, at least 350-400 V DC voltage (the application requires 320 V, so naturally, I don't want it to be barely on the level). The current rating is also important. If it can be 1 A each, then that would be great. 500 mA is also fine, because I can use them afterwards in parallel and use load balancing resistors. 

So, why am I asking this? First, because I have a few applications that could use such particular transistors, so it would be nice to know about them, and second, I want to try and drive a 5 HP 320V motor, a continuous DC servo motor to be exact. Of course, I know that there are dedicated circuits for this type of applications, but due to the specificity of this particular board, and where I live in as a country, they aren't just readily available. So, I wish to try and construct one on my own. Naturally, I know about the PCBs, soldering, etching solutions, etc., so those aren't a problem. 

Also note that I am intending to use the transistors stated in parallel to be able to increase the current throughput. Now, I noticed the BUL743 transistor, but the thing is that there is a power limitation. From the datasheet, it says that it can handle only about 256 W, but I could be wrong. So, any ideas about transistors, and any inputs on the project itself? Much appreciated :)