Hey Chaz,
You were very smart to take it to the dealer and have it checked. I bought my 90 from a friend for six bucks and it had 120,000 on i and wish I had done that before I bought it. That was two years ago and I am still happy even though I have had a few issues such as suspension, power steering and AC. The AC is something they want a fortune to fix but it looks like I can buy a compressor pretty cheaply and I have 30lbs of R-12 in stock plus all the equipment available to repair it myself.
Here I my suggestion for whatever it's worth. I would read every post on this site regarding the LS400. Once you are very knowledgeable on the problems and symptoms typical of this car, I would use something like autotrader.com and start looking. When you start going out and seeing what is available and the prices, you will be prepared and able to make a quality decision that won't lift too many $$ from your pocket. It is your money and I'm sure you worked very hard for it. Buy exactly what you really want. People are so full of BS about cars that you can't believe anything, so know it yourself first.
Welcome to LOC. Our strength is the top quality people who frequent this site. We watch each others back.
Denny