Hi Badhan, you may note that most users here are in the US, tho not all of course as we are truly a global family, so your posting came up in the overnight/morning hours. We all needed to get our coffee before responding.
Yes, the W210 would suit a young man better as it is more updated and stylish, but as stated it has more electronic systems to contend with. Another advantage is that it will have more updated safety features, more airbags, better braking systems and suspension, and the like. You did say "because in our country repairing would be a problem" which may mean the simplified, older W124 is better suited to you for practical reasons.
The W124 is an older car and the age/mileage alone may mean that more mechanical parts are worn out and may need replaced. Of course, replacing those parts can be done by mechanics who are "old school" and perhaps more familiar with these classic Benzes than their newer, fully electronic cousins.
The best advice is to go and drive each car and see what speaks to you. I was considering a W203 but chose a certified pre-owned W202 instead after driving one. Simply by looking at the cars, I never would have guessed that I would prefer the older model, but I remain content and fully satisfied with my choice. Let us know your decision and share pictures once you have added one to your stable.