mark and lable all the part like rods and valves when taking it apart. you never know when you may need to use something you never thought you were going to need. Zip lock bags with the white labels so you can sharpy right onto the bag whats inside. Also keep all of the bolts dont loose or toss them out. But do buy a bolt kit from jegs or ebay and replace them. You just never know when your going to need that random bolt. Buy gaskets in master engine/complete sets.
KISS method = Keep It Simple Stupid, is the method of choice. Make sure you have a good car that is worthy of a strong engine good brakes and tires. build the engine during the day dream of hp numbers at night. In other words dont go for broke on the engine when the budget is not going to allow $10K worth of upgrades before you can put big power to the ground.
Im not a ford guy but usally stock style cast pistons will do the trick. Also dump the roller rockers and just use some stock heads unless you can find a deal somewhere. you can probably find the manifold on ebay rpm or rpm air gap will work ok the regular rpm may even be better if you plan to drive in cold climate or heavy traffic.
You should be able to buy a complete engine rebuild kit with the rings and pistons included.
Have inspected the bore does it have any type of lip at the top. Not carbon but iron that has been worn away. you should see some unless its freshly bored or low miles. If so it will need to be bored and honed for new pistons. if that is the case wait to buy pistons until you speak with the machine shop. Always bring a bare block to the machine shop its cheaper and easy to take apart and also be sure to search out the best price for the bore job not all machine shops are equal and neither is there work. Best to shop around a little and talk to ppl that have had some work done in yur area.
Sorry for the long post hope it helps.