Im planning on putting disc brakes on the front so this will have to be plumbed in eventually. And it will only be in this configuration driving around my yard as it will have front disc's by time it hits the road.
What do you think?
Now there's some info that would have helped earlier..
In that case I would recommend 3/16" lines to the front.
Also go ahead and complete the system in preparation for the disc swap, use the proper lines and valve for that setup.
Then assuming you really won't be driving any more than in the yard you should be fine, you may not even want to hook up the front drum brakes and don't put any fluid in that part of the MC, then carefully drive around the yard as needed, and plan on that front disc conversion before the truck is on the road.
Grigg