David,

Since an original (optional '66) engine was a 289 with a front sump oil pan, You would be better off sticking with that arrangement. A rear sump pan may not clear your lower frame parts or steering system. Getting a front sump pan will require a different oil pump pickup. Front timing covers are pretty much interchangeable between early 289's and later 5.0's (302's). Original 289's were standard rotation (CCW from the drivers seat), later model 5.0's were "reverse rotation" (CW from the drivers seat). Also, later model timing covers don't have provisions for an oil dip stick as 5.0" were on the drivers side of the block.
You can mount a "standard" rotation pump on the later serpentine front cover but you'll have to find pulleys for the water pump and the crank (both serpentine), which will have four holes instead of the earlier 3 hole 289 style (V-belt). They're are universals around with both hole configs.

As for the dizzy, whatever you decide on, you ABSOLUTELY need to verify that the dizzy gear is steel if you stick with the steel "roller cam" that comes with the later 5.0 engines. IF you swap out to some other cam configuration, run the bronze gear for compatibility. DO NOT RUN A STEEL GEAR on anything but a steel cam. Earlier Durasparks are good but mount the control module as far away as possible from any heat source. It will come with an iron gear.

Doc