do you think you can get serious bass slam with HE1000SE?
I can't speak for the SE, which I've not heard, but the HE 1k v2 was soft in the bass. I liked its bass a lot as it had plenty of sub-bass depth and texture. But it didn't have much mid-bass punch, and it isn't the headphone I'd pick for slam.
With the right amp, the Final Audio D8000 can slam quite impressively. The ZMF Caldera can, too - again with the right amp - but I found the Caldera to have an overly damped sound. If you don't mind a dynamic rather than a planar headphone, the Atrium slams like a beast, but it doesn't have much sub-bass depth.
I think your best bet is an Abyss 1266. They're not as difficult to drive as people suggest (a stronger amp helps but your Voyager should be fine), and they hit hard. I realize they're expensive but I bought my old 1266 Phi with upgrade CC pads for under $3000 used, and there are a couple of TC models for sale here in the classifieds for $3300, which is a decent price. I don't recall hearing of problems or complaints re. 1266 drivers dying; my sense is that the Abyss headphones are well made, but of course buying used poses its risks.
I only heard it twice, briefly, and at audio shows but the Modhouse Tungsten has outstanding bass, with plenty of slam. I heard the single sided version and really liked it. It reminded me of a less dark LCD-4, with better (i.e. more balanced and neutral) tuning, similar levels of resolution, and a more open and spacious soundstage. The downside is the ca. 20 week wait...