eBay usually has vendors selling the spiders and dog bones. You'll also need a cam retainer plate to match your block, it's held on w/button head screws for clearance. There were two different widths of cam retainers so get the right one to match your block. If your block isn't drilled for the retainer, either retainer will work.
Push rods are about 7.2" long for the hydro roller, FT cams used a push rod about 7.8" long. The exact length will be decided after you mock up the engine using the cam, heads, valves, head gaskets, rockers, rocker studs, etc. you intend to run.
is one of many threads on valve train geometry.
is a list of valve train points to check.