I am wondering what lug bolts to get. I have a 1982 300D-TD that currently has 15" rims. I am getting 14" rims that I believe are alloy. Also am planning on getting steel rims for winter tires. In the owners manual it shows 2 different bolts, 1 for forged light alloy rims only and the other for light alloy disc rims/steel rims only. All of the places I've shopped on the Internet list only lug bolts for either alloy or steel rims. Do I need two different sets of lug bolts since I am planning on using different type of wheels at different times of the year?
Below is a picture of the wheels that I am getting.

the steel rims use a shorter bolt than the alloy. the longer bolts can be used on ther front only with the steel rims, if you use the longer bolts on the rear with the steel rims they will damage the parking brake hardware inside,