I have an 03 Accord and Honda is using 5-20 oil for their newer models. I plan on using synthetic oil after 8-10K miles. Do you know who makes 5-20 synthetic oil or if it's available?

Mobil has 5-30 and 0-30. I may have to go with 5-30 oil if 5-20 is not available. Any negatives with using 5-30 oil?

Thanks,