I noticed the tag is for in-game. If so, that's a lot of effort, frankly, for a suicide role. In fact, apart from a niche role in the lower tiers, this set is odd, but to be fair, I really, really like it, because it's so specific, and well, different.
Anyway, on to your question. This depends on your opponent's Pokemon, I suppose. If the opposing Pokemon is a sweeper, then you're best off using another Pokemon to dispose it, considering its defenses might be frail.
That leaves other Tanks and hard-to-take down Walls.
Tanks can take hits and hit back comparatively hard, so in that case, both HP and Defense are important.
However, Walls rely mostly on passive damage, so HP loses out because, well, passive damage is % based, as opposed to actual HP. That leaves out Seismic Toss, which is a specific case where HP is important. Just barely.
Honestly, looking at all of that, I suggest the first, more mixed spread. You don't really need max HP, if your Lapras is going to stay in and faint due to the Perish Count falling to 0, in which case no amount of HP is going to help you. The mixed spread might help you survive a turn or two longer.
All in all, the results are confusing and slightly inconclusive, but that's because there's no real threat or counter to this moveset, nor a specific target, so you don't really have much to compare it with.
