Hi and welcome to NICO!
1. Search, alot of topics have been discussed over and over so you can almost always find answers to your problems before hand. Use the red button in the upper right
2. Invest in a FSM (Factory Service Manual) I have a Chiltons manual and I like it. It will help to give you a step by step on how to fix your 240 after you've diagnosed it. Very handy tool as it gives you torque specs for many bolts.
3. Feel free to ask questions, chances are someone has had the same issue earlier in life and can save you some heartache and money.
If the whine is a high pitched noise that happens at higher engine RPMs then the belts more than likely just need to be tensioned. However take a look at them... if they are frayed, cracked, or appear to be glazed and old then it's replacement time. The FSM (see no. 2) will outline how to do that (it's very easy and requires a little patience and some common handtools).
As for the suspension, a popular setup on the 240 is a KYB AGX adjustable shock/strut setup w/ a popular lowering spring such as the Eibach Prokit. It offers adjustability, which is a MUST in my book, and it gives a firmer ride without the harshness of a full coilover setup.
I also suggest you replace the suspension yourself. It's as easy as changing the oil

... more time consuming but if you can turn a wrench and follow instructions then changing out suspension is easier than you'd think!