Why don't you just buy the parts from the LBS? Because you bring them your bike to insure proper size and style parts (like balls and ders) doesn't mean that you have to let them do the labor too. In fact I enjoy helping customers who do their own work. they become my most informed customers and really appreciate my hints and advice (that comes for free BTW).

The rear wheel balls needed will be the same size that is in there already, likely 1/4" x 9 a side. But you need to confirm this as I don't have telescopic X-Ray vision. The der needed will have to have the same type of attachment design and be able to handle the cog sizes (front and back). If the levers are indexed (which I doubt given the old Sun Tour Perfect freewheel) then the der will need to be within the family of compatibility for ST indexing. If not then any brand that matches the cog teeth capacity will do.

All this would have be found out in about 1 minute to discover if the bike was in front of the LBS. Andy.