Hate to be the bearer of bad news but the N62 engine is not a 'bulletproof' BMW engine. The VSSeals are a known failure item at low mileage.

To my knowledge, there are no after-market seal kits for the N62.

So this begs the question. Tear down the engine, fix all the other stuff that can go wrong too: Timing chain guides, gaskets, rebuild the heads, coolant pipe!!(another freakishly expensive failure item due to shitty seals and not so great design-from a longevity perspective) and of course the valve seals - If the seals are the same as the original then why bother? Based on my experience they will go again at 45 k miles and I just spent a shit load of money.