For simplicity and as Larry mentioned cost, you can't beat the HEI that was run in the 250 in the late 70's. Get the one with the coil in the cap and it will take all the hi-po parts that the small & big block Chevy V8's use. There are modules, advance kits, hi volt coils, adjustable vacuum units, all at reasonable prices. Top it off with a quality cap and rotor with brass contacts and a good set of 8mm wires like Taylor Spiro Pro and unless you are all out racing you have a hot and dependable ignition. Another plus is if it ever needs service while you are out on the road you can at least get original type parts to get you going again at any auto parts store.