First of all, please do not listen to what any regular petstore tells you, many hire incompetent employees... thus it's hard to find a GOOD petstore that knows what they are talking about. (you might want to consider finding a better place to shop at)
Second, if you had to handfeed the chicks, how would they [the wild birds] survive in the wild without someone to raise their own chicks?
Thirdly, if you do decide to handraise them (not that you need to), you need more supplies than handfeeding formula and a syringe...
Here's an
inadequate list of items that you should have on hand to handraise...
Proper Breeding Cage or a Large (flight) Cage
Pipettes
Syringes
Handfeeding Formula
Wooden Nestbox
SAFE Nesting Material
Incubator
Brooder
Scale
Thermostat and hygrometer
Thermometer for checking how hot food is
Heating Pad
Heating Bulb (i.e. Ceramic Heating Lamp)
Paper Towels
Humidifier
If you don't or can't get these supplies, or the experience needed to handraise babies, then you should have a few avian vets and breeders on hand/call in case of an emergency and chicks need to be handraised. To give you an idea, newly hatched chicks need to be fed around the clock every 2 hours, and as they get older the time between feedings increases... however it doesn't stop until they are 5-8 weeks old, sometimes older. Basically going from 12 feedings in a 24 hour, to maybe 9 with a bit rest at night, to six, later on to only 3 feedings a day, then only 1 until weaned.
Here's a list of great articles of Winged Wisdom/BirdsNWays website on handraising etc...
If you read through the articles, you may read that although there may be some benefit to handraising them, there are also dangers when improperly done.
You can find more information (or rather links to info) here... (same page but different links)
BirdsnWays - Articles & FAQs on pet birds, pet parrots & exotic birds - Breeding Birds, Mating, Weaning, Eggs, Nesting
BirdsnWays - Articles & FAQs on pet birds, pet parrots & exotic birds - Breeding Birds, Mating, Weaning, Eggs, Nesting
Thus, my suggestion is to leave the parents be, and let them raise the chicks. When they are about 2 or so weeks old, you can take them out of the nest a few times a day (but no longer than 15 minutes) to socialize them and put them back. As they get older you can increase the time that you handle them as they will be growing feathers. At about 3-4 weeks of age they may act as if they want nothing to do with you... however this is only normal behavior for chicks. Just keep interacting with them and they will be tame as adults, as long as you keep interacting with them as they mature.
And, by all means, congrats on the chicks!