When I got my DT50 about 4 months ago I had 3 options for switching:
1) Standard foot switch between 2 channels
2) POD 500HD or HDx
3) MIDI Foootswitch
I decided to go the MIDI route even though it is the less used of most configurations. I am glad I did, after a lot of searching I found these.. While they are a bit pricey, they do anything you need MIDI wise and it can send up to 20 MIDI commands to control the DT50 or DT25's settings. I tried some other lower priced options but this really does anything you need and once you use it you will be glad you grabbed it, I know I was..
Liquid Foot MIDI Controllers
You can basically change any parameter and not have to save anything to the amp, So if you want a JCM800 but with Pentode and Class A you can do it and control volume, drive, EQ, etc all with one foot switch press.
They also have a good Windows/OSX editor so you can do everything offline and then send it to the foot switch instead of programming the foot switch with the buttons itself.
You can also setup set lists/songs, which I am in the process of getting done myself so I can hit one switch and change any other MIDI gear I have and change the amp as well for different parts (solo, verse, bridge etc). So no tap dancing...
I hope this helps!