Maybe It's just me, but your internal wastegate usually has a 'vaccum' line all by itself, usually it comes right off the compressor for an internal gate. So you wouldn't have to buy that one.
Saying that, all you have to do is run vaccum line to the bov from the IM, you can T into a line for the FMU. Id say that would depend ALOT where you put your BOV, I'm putting mine right after the intercooler because I don't want it to be very loud, so I would need more line.
Also, it depends where your guage is in your car and how you are going to run the line. No matter what, I'd say 50ft is alot more than enough, 50ft is a lot of hose, are you going to rework the entire system?.?...
Wouldn't it be easier to goto a local hardware shop and buy like (a foot or less) of some different tubing sizes and see whitch fits better overall of your components, there are tons of different sizes that everything in your car and on your turbo could be, and alot more that would work but that aren't exactly the right size, you know the; "I'll just clamp that one down", and the "Boy thats a tight ass fit" ones?
Thats what I do:
Buzz1167
Jon N