I'll apologize in advance for not really answering the question, but I'd consider other options before going to a 4 bag setup with tiny front panniers on low riders. Here are a few options, most I have tried and liked okay.

1. Using a bar roll with no front panniers. I have done this with various setups on the back.
2. Using a handlebar bag with no front panniers. I have not actually done this myself, but it was once very commonly used and still isn't unusual.
3. Using a tiny platform front rack with no front panniers. I did this with one of those tiny racks that mount on canti brake bosses. It worked great. It has carried a variety of bags.
4. Using regular front panniers and skipping the rear panniers. I loved this setup for a light load, but abandoned it when I went ultralight and stopped using panniers altogether. I'd still consider using it depending on the bike and the load.