Control of large number of analog devices
a 1MHz current source is not the kind of thing you can easily DIY, instead you would probably be looking at a current output DAC, even then setting time and non linearity will take some careful planing to ensure you can reach that. 

For the LVDS, it will come down to what kind of voltage range you need, and what response time you need, to get n bits of PWM resolution generally takes a modulation frequency at least 2^n higher, 

You also have not given an idea on budget, as a 1.7 MSPS 8 bit voltage DAC in 100 units quantity is about $1.60 each from a quick search, so you could always throw hardware at the problem for not to high a cost.