My dad has an 04 6.0 with 116*** miles on it, he needs new shocks and i recommended Billstiens. Where would be the cheapest place to get them if that is the shock he should go with? he is also having a problem with it when he starts it up and it is cold, it blows out white smoke and can hardly move under its own weight till it has warmed up for at least 20 minutes and it still takes about 20 minutes after that for it to run like normal, it has no power for the first hour or so. Thank you in advance