Go to a wine store & get Private Preserve. Its a wine preserver thats completely safe, prevents oxidation(OF YOUR BUD) by using inert gases. argon AR, carbon dioxide CO2, and nitrogen N2. Unless you believe your vacuum sealer will suck every last atom of oxygen out of that bag, some oxidation will occur I suspect so this SHOULD keep that bud nice and fresh
Bottle can't be to much and says 120 uses, so sounds like it should do the trick for your situation
I believe you'll be fine without anything either, vacuums sealer will work just crunch the bud down and compress as much of the air out as possible