Buy A roll of 3/16 copper nickel and a load of fittings. Trust us, if rust is an issue on your truck (it is) then they all need doing. It's so much easier to get into the mode and do all of them at once, flush all fluid and bleed them , than it is to deal with parts of it every 3 months.
It'll just be very wise to secure another ride for a while or else you will be checking your watch and trying to make the work fit your time window. This is not the kind of job for that, lots of measuring, lots of mock-up and re mock-up , lots or corrosion protection work etc. The paint and...