DHA is definitely the "good stuff" in this case and let me explain why. In biochemistry, sometimes it's much easier to get from point A to point B but it can be hard to get from point B to point A. This is the case with converting DHA to EPA and vice versa. It's much easier to convert DHA to EPA than it is to convert EPA to DHA. Comparably, the conversion from EPA to DHA is poor. So I would try to maximize DHA intake and your EPA needs will be taken care of.
This is also why ALA is a poor source of n-3 because the conversion to DHA is worse than 1%.
DHA is the stuff that has been shown to feed into anti-inflammatory cytokine pathways.
1.7642 to 1 of DHA to EPA.
Actually, DHA is the one to more heavily balance if you have the ability to prefer one over the other. As Jon has stated already, both are far preferable to ALA, though you can google ALA conversions on Google Scholar and get differing rates.
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