Liliana's Specter and Altar's Reap i'd say. Seems a decent build otherwise. +1 from me.

If you're feeling generous, give Tartarus Sauce a look and give me your thoughts.

I'm looking at either picking up a Scrubland or a Liliana of the Veil. Let me know your opinions.

Hard decision. Both will maintain value, no doubt. The Scrubland would definitely make your mana more consistent, though I doubt you've been having many problems in that regard. Lili just immediately takes over the board. I guess it would depend on how competitive your meta is. If you want to win, ask yourself how often you need that Scrubland. If the answer is that it often would not matter, I think your better choice if with Lili.