with a 3.40 stroke, about the longest rod you can run is 5.4". cam is up to you depending on what you want from the engine, what cylinder heads and intake you are going to run, etc.
Coast high performance has some options for stroker kits for your engine: http://www.coasthigh.com/Ford-347-engine-kits-reverse-dome-s/130431.htm
If you want to run an 8.2 deck I would go 347 cubes and run a shorter rod so there's more room for the ring package in the piston. There's a lot of subjectivity here. It all depends on your risk aversion, budget, etc.
Your questions give me the impression you don't know much about engines. The most important thing in my opinion is to consider what you want from the finished product (street only, race only, combination, 1/4mile, road racing, manual transmission, automatic, etc), what is your budget and then you can decide what are the best parts to buy. Don't buy one thing at a time until you have a plan/goal for where you want to end up.
If you buy a stroker kit but don't have a good set of heads, intake and exhaust - you won't see much if any gain. To pick a cam is a huge deal. If you don't want to take time to research yourself, I would recommend you call Comp Cams tech line. They will want to know a lot of details about your car including rear gears, weight of the car, tire size as well as all the engine details and your plans for usage of the vehicle. It's a lot of information to gather to give to them, but they need it in order to pick the right camshaft for you.