What to do with my reynolds solar Hot Water System

Marc, if the tank is leaking get rid of the external heat exchanger that is on top of the tank  along with the tank, scrap it and just get a new tank with a built in heat exchanger. There are many to choose from these days. I usually reccomend a Superstor. If the panels don't leak and the controller and pump still work, then continue to use them. You may just have to redo some piping at the tank, and you can reduce to using only one circulator pump.

Marc, just do an internet search, you should be able to find someone in the area. If not, just get a local plumber. If you explain what needs to be done, he should be able to do the job. Basically, cut the two lines heading up to the panels and reconnect them to the heat exchanger coil. Just be sure to add a couple of boiler drains for filling and purging, a check valve between them and the pump all in series near the tank on the lines heading up to the panels. Put the sensor somewhere on the tank, middle if possible, and plug the pump into the controller.
  Then cold water in and hot water out to an existing, backup hot water source.
 There are plenty of diagrams for systems on line. Just do a search. Home power magazine has plenty, as well as other hot water sites...