This is my first post, so hopefully i have gave enough info to get started, here we go and thanks for any help

I'm in southern ohio with an un-obstructed southern view, I have installed 2500 ft of 5/8 pex, 10 250 ft loops in a 40 x 70 ft with 16 ft side walls, 6 inch slab, no insulation under, approx 18 inches of gravel base under concrete, edges will be insulated with 2 inch foam, walls will be pole barn style metal over 1 inch foam, ceiling will have minimal insulation, 1/2 inch foam or just osb,  i will be building 10 4 x 10 ft solar hot water collectors, for a total of 400 square ft of collector to start, that will be mounted vertically to the southern side of the building, also have a 1000 gal stainless tank that will be insulated in the building for heat storage, i want to use this building  mass as a furnace that is 100 ft away from my house, built in1939, very poorly insulated, want to do over sub floor radiant heat under laminate flooring for the thinest heat resitance but also have many castiron radiators.
heating the 40 x 70 is secondary to heating the house if possible
any sugestions on collector runs series or paralle whats most advantages for heating up the fastest
any help/info appriciated

Is there any thing as to much water storage?

The panels should be of the grid type and not serpentine, as some people do. Bottom in, top opposite corner out (of the assembly of 10 panels). The panels should be in parallel so that the bottom header (1" min, 1.25" is better) is straight through from the first panel to the last. Same with the top header, exit should be opposite of intake and should have a provision for a sensor well that can be inserted into the panel. The risers should be no more than 1/2" copper. I don't know what you are using for the fin material but it is important in determining the system output.

The big issue is freeze protection. Will you be putting glycol in the system and with what size of HX between it and the tank. The tank will have to be protected from freezing and you cannot rely on the solar to do it alone.

There are so many solar panel company which can help you out, so its better you take help of the rather then doing it on your own.

Don't know if this is what you're looking for, but apparently AEC Daily offers alot of FREE courses about solar systems, you might want to check it out! http://aecdai.ly/4y

http://www.builditsolar.com/Projects/SpaceHeating/DHWplusSpace/CollectorConstruction.htm