1. $350 should be a negotiable price...If a decent mechanic charges 70 dollars an hour, this job should only take 2.5 hours. You just need one socket, a two foot or three foot extension, and a socket wrench. You take the TB off with the turbo, then separate when you are done. The hardest part is knowing where all the hoses go. If you can, lable all the hoses and pipes prior to bringing it to the shop, then have it disassembled to save the mechanic from wasting time.
I took my turbo off two weeks ago and it took me less than one hour. Granted, I've done this process at least 5 times, but I guarantee you, I am no professional at this at all and one hour seemed too long to do it.
If you were to put a new turbo on at the same time as the removal of the old one, then a 3 hour job is the maximum time I would give any mechanic, being that all he has to do is swap the TB, maybe the exhaust elbo, grease the parts, seal it up, and put it back on. $350 is ok, but I think you are being overcharged.
If you know your mechanic well, and have time to spend at the shop, I am sure he will give you a break on that price if you hang out with him while he works on the car.
2. As for the Oil line, POSTON has a nice braided line for the cars, but I am not too sure of the length or application. On their website, it is just listed as oil feed line. Check it out or contact them and see if it is what you need. Good luck. Hope all goes well with the car!!
John