I have gradually replaced every metal brake line on my rust-bucket GMC & on a rust bucket Fire Bird that I used to own & I always just went to Advance & bought the stock line that they carry & bent it myself to fit. I found it to be somewhat time consuming but not crazy difficult. $120 sounds like a real good price if that's for everything & prebent should make the job a lot easier. Quite often the fittings on those old lines will be corroded beyond recognition & if you can get a pair of vice grips on them that helps. If not, I have often snipped the old brake line at the fitting & pressed a 6 point socket on to the fitting. As far as advice specific to a Dakota, I have none because my Dak has never seen salt, but in general I would agree with the above poster's advice of using a GOOD penetrating oil. Kano Kroil is the best that I have ever personally used, expensive (about $100 a gallon from Amazon) but, imho, worth it ("don't spoil it, Kroil it!").
Many moons ago I changed a brake line on an old Taurus that I no longer own & I did a real nice job of removing the old line & clamping the new one in every place I could get a clamp. Now I don't bother to take the old one out, I just leave it where it originally was installed & instead of using clamps on the new one, I go with multiple tie-wraps & tie it to the frame or even the old (now dormant) brake line. There is a right way to use tie wraps & a wrong way -- the right way would be to put a tie wrap around the brake line & then one around the frame (or whatever) & then use a third that goes inside the first two tie wraps. This way you are not tying the new brake line directly to the frame where vibration may gradually damage it, but you have a stand-off of sorts between the new brake line & the frame (or whatever). You can buy extra long tie wraps, but they still won't probably be long enough to go around the frame rail, but you can put two of them together to make a super-extra-long one. If you did it the wrong way you would probably be okay, but the way I just described is the "aviation way."
General advice would be not to clamp the line anywhere until you have both fittings started & not to put final torque on either fitting until both are started & finger tight. I'd also say that prior to fishing the new line through any tight spots it is going to have to go through, to put a cap or some tape over the fitting to prevent you from inadvertently getting any nasty shit inside your brand new line & all the potential issues that could create inside your system.
I'd also probably say, in general, to do & complete one before you started on another one.
Also, to change one, bleed it, change the second one, bleed it, & so on. But that could just be me. If you did it that way you should still go around & bleed them all a final time after you get the last line in, but I still think it might be easier to get the system bled that way. I believe that in general you are supposed to bleed the brake farthest from the master cylinder & work your way in to the master cylinder. Also, I don't even bother to ask my S.O. for help on bleeding brakes anymore (too much bitching & grief), so I have some pieces of 2x4 cut to the right length to hold the brake down after I pump it up. That is also time consuming, but to me, the peace & quiet is worth it.
Good luck with this.