Although I haven't done this myself, I plan on doing it and have done plenty of reading on it. From what I understand, yes, you will have to replumb your brake lines from at least your distribution block to add in a proportioning valve. The proportioning valve is used to regulate the brake pressure going to the rear brake lines. Set this valve to ensure your front brakes lock up before you're rear brakes.

Because of the offset from the firewall after adding the booster, you will more than likely have to replumb your brake lines from the master cylinder to your distribution block as well unless you find some sort of pre-made kit. At a minimum, I'm pretty sure you'll have to replumb your lines from the distribution block to each front tire. I would recommend taking this opportunity to upgrade your master cylinder to a two-reservoir type assuming you haven't already done so. Using the two-reservoir type M/C will separate your front and rear brakes into two different circuits. That way, if you experience failure in one circuit, you will still have braking power via the other circuit. With the single reservoir type on your car now, if you experience brake failure, then your screwed.

You should only have to replumb your lines in the engine compartment. Replumbing the lines isn't really a big deal. If you don't have a double-flare tool, you can just pick up a tubing bender and buy pre-made lines in the different lengths you need from just about any decent auto parts store. These lines will have the flares and the fittings you need already attached. All you'll need is a tubing bender. You can use an old coat hangar to mock up your lines and figure out what lengths you are going to need.

I'm looking forward to getting this done myself. I'm still torn between going power or not. I'm definitely going with front disc.