I'm going to assume that you wouldn't want to buy a bottle of sriracha if it's something that you find too spicy ... and it's impossible to find something that's truly 'similar' in taste without it being hot.
So instead, I'd consider basing the sauce off of "Sweet Chili Sauce" that you can often find in the Asian section of American grocery stores. (sold by a few different companies -- Mae Ploy and Lee Kum Kee are typically available near me)
Although it also has garlic in it, it's not quite as strong as Sriracha. In other recipes you might want to add a little to compensate, but the recipe already has three cloves in it, so you likely won't miss it.
You'll also need to reduce your sweeteners (it's sweet chili sauce, after all). I'd try making it without the honey, as the chili sauce is likely going to add the sweetness of about 1 to 2 tsp of honey. (if needed, you can always add a bit after tasting).