To solve this problem, we need to find all combinations of 4 numbers from the given list that sum up to 1803. The provided numbers are:

$\{200, 245, 300, 310, 318, 325, 360, 390, 405, 405, 435, 440, 442, 460, 490, 525, 545, 680, 680\}$

We can break this down into combinations of 4 numbers at a time and check their sums.

Let me compute this for you.It turns out there are no combinations of four numbers from the provided list that sum to 1803.

Would you like me to try a different approach, or clarify anything further?

Here are 5 relative questions that might interest you:

1. Would you like to explore combinations of different numbers, such as 3 or 5 numbers?
2. Could the target sum be different, and would you like to find the closest match?
3. Are there any constraints or limits on repeating numbers that you would like to add?
4. Would you like to explore this with a different set of numbers?
5. Is there another specific total you'd like combinations to add up to?

Tip: Sometimes slight variations in input (like allowing repeated numbers) can drastically change the solution possibilities!