A lot of the best cards will have more than one colored mana in their mana cost, so you'll probably want to focus on one color and splash the other. It sounds like you're going to focus on black and splash white (unsurprising for vampires), so I'll try and make suggestions in that vein.
Read the Bones and Sign in Blood are good for card draw, but they're even better if you're also gaining life to offset their life loss.
Divinity of Pride is a solid lifelinking beater. You'll need solid early lifegain to get the best use out of it, but it's still decent even if you don't break 25 life. Blood Baron of Vizkopa is similar; which is better depends on your metagame.
Sanguine Bond and Vizkopa Guildmage have synergy with other lifegain effects. The Guildmage has the advantage of also being a cheap body.
If you have enough lifelink, I would abuse Drana, Liberator of Malakir. The first strike means that your creatures get their counters after she deals damage, but before they deal regular damage. It can help with close battle numbers. If you're gonna play vampires, you gotta play aggro.
Any suggestions for good cards? (I already know Nighthawk/Gatekeeper)
Looking at vampires, Tithe Drinker seems obvious here. Drana's Emissary isn't terrible. And Kalitas, Traitor of Ghet is just ridiculous.
Read the Bones and Sign in Blood are good for card draw, but they're even better if you're also gaining life to offset their life loss.
Divinity of Pride is a solid lifelinking beater. You'll need solid early lifegain to get the best use out of it, but it's still decent even if you don't break 25 life. Blood Baron of Vizkopa is similar; which is better depends on your metagame.
Sanguine Bond and Vizkopa Guildmage have synergy with other lifegain effects. The Guildmage has the advantage of also being a cheap body.
In white, Archangel of Thune isn't really budget, but it's stupidly good. Ajani's Pridemate isn't terrible either.
Removal spells include Mortify, Unmake, Oblivion Ring (and friends), Hero's Downfall Anguished Unmaking
Hand disruption includes Tidehollow Sculler, Duress, Despise and if you're not on a budget: Thoughtseize.
Throw in any of the Sorin PW's for extra fun.
Sasky for the Sig.
I am in your [PACK]. Watching you... do... something.
Already mentioned in the original post.
Mook's Cube!
Mook's Frontier Atarka Red Primer!
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