I went through this last summer on mine and in the end I went for the OEM replacement lines from Porsche. Unless you take the time to make up new hard lines which can be done if you source all of the metric to JIC/AN fittings (typically Porsche uses metric fittings where as the industry standard for hydraulic fittings and hoses is based around imperial), then anything else will probably be a bodge. I've found some terrible examples of this on the web where people have carried out repairs using flexible hoses which I just wouldn't trust.
Porsche lines are expensive yes, but they save you an awful lot of time and faffing around. Plus they are safe and will last 30 years or more, so when you look at it that way they're actually not that bad in terms of value. Do it once, do it right.
This is coming from someone who is normally happy to make my own parts to save money, but after looking in to it I decided it just wasn't worth it. Although I will say the cost is probably easier to justify on a turbo... My bill for all the hard lines and flexis came to just over £400 and they were a doddle to fit, no faffing whatsoever.
You'll probably find the axle may have to come off any way as many of the hoses are difficult to get to and the fittings will very likely to be badly corroded. I'm afraid it's not a nice job which ever way you look at it
