Joe - a couple of things.
With kits you really don't need to rack that much; once you have stabilized and the wine has cleared, you can rack off the sediment. If you are bulk aging for awhile then you really don't have to rack again until you are ready to bottle. Racking too often can lead to oxidation, especially with white wines. As mentioned by others, you should add the whole packet of sulphite when you stabilize and then, at some point before you bottle, add another 1/4 tsp, assuming you will be keeping the wine for more than 6 months, as probably mentioned in your instructions.
Also, making your wine to less than the recommended 6 US gal is not a good practice, especially if you are making premium kits, since it upsets the balance of the wine, and may not allow it to reach its full potential. A better practice, would be to make it to the 6 gal and then rack to your 5 gal after stabilization and put the remainder in smaller bottles ( gal, 1/2 gal, reg bottles, etc.). Also, check out threads on topping up to find out how others are dealing with this and keep your eye out for used mexican carboys also as these are closer to 6 gal.
Good luck.