I would suggest this build: http://www.torhead.com/skill-calc#800rfRRodcdkqZMco.1 - 2 points to spare
Kolto Residue - I find useless as you'll rarely take advantage of ever healing more than one target with the residue bonus
MedZone - I don't find worth the two points as it's situational as well, Treated Wound Dressings is better use of these points.
Ironsights - A must have as mentioned by another because the more AIM the more heal and crit you'll have.