Audio in wind requires the tools it requires. That is, physical wind prevention on-location, not "after the fact" fixing unless there truly is no other way. There is a reason Rycote is in business after all these years...
Even for mild wind, I use a small condenser mic with its own foam screen on, and then the ball screen from Rycote around it. It is very effective, but only up to a certain breeze; that's just Nature and the laws of physics doing their thing.
If you get a DSLR for this purpose, make sure it has a decent plug for an exterior mic (as you mentioned) that can be mounted in the hotshoe. Then look at third-party wind screens that may fit the mic and give it a fighting chance. It may look bulkier than you would like,, but it truly is a matter of either/or: you either really try to prevent the wind from coming into the mic, or you will have audio that is, at best, awful-sounding when the wind hits, and then you are down to trying to "filter" it in post, killing some of the good frequencies in the process.
Some things have to be stopped "at the gate" by physical means in order to get usable results. A low-cut in-camera filter will take out some of the low-mid frquencies, but it will in no way stop even moderate wind blasts from ruining the sound.
Good Luck.
Claus