There was a company making 37s a few years ago. Rumor was the 37s were cracking under heavy load. You want less that a 38, I think you have to go compact. I can't remembe the name, though. Perhaps I should add "old and senile" to my moniker.
Other options are an IRD 12-28. Heavy, but much more useable than Shimano's 12 27. IRD's last 4 are 21, 23, 25, 28, vs Shimano of 19, 21, 24, 27. You could consider a Cycle Dynamics cassette, too. It has individual cogs. I have an 11-30 for a big hill climb. With a few extra cogs, I run it as an 11-21 most of the time and 11-30 (11, 12, 13, 15, 17, 19, 21, 24, 27, 30) twice a year. It works with both D/A and Force. It's very close with the Force, but it does work. Disadvantage is expense.