I am happy to help and share what I have learned. You don't need all 4 stages, you don't need the whole circuit, just the MCP1403 / 7 or similar Driver IC and a few resistors and Caps would be fine!
I believe Netduino is the only current .NETMF Controller on the market right now. GHI Have one of two but I don't know anywhere selling them.
It is possible to port the .NETMF to another Microcontroller with GHI Electronics .NET TinyCLR OS, but this is a bit much for now.
A very simple PWM would be:
Microsoft.SPOT.Hardware.PWM MyPWM = new PWM(Cpu.PWMChannel.PWM_4, 2, 0.01, false);
All that's required is to import the Microsoft dll:
C:\Program Files (x86)\Microsoft .NET Micro Framework\v4.3\Assemblies\le\Microsoft.SPOT.Hardware.PWM.dll
Of course this is a very simple layout, took me no more than 15 minutes. The Driver IC is very easy to use!
The HUGE benefit, I can easily program the Micro to a huge range of parameters and easily save the settings for my records. I can share software also if you decide to go down this path.
This is really easy. I am more than happy to help, sharing is where we have a huge edge!