Yea, either cam will work. There are no hardened valves, you're thinking of hardened seats. That's going to substantially add to the cost and if you're going to build another motor in the next year or so, that's really money wasted. That is unless the heads need new seats. But you might be better going with the aftermarket heads now and reuse them on a new short block later instead of pouring money into your stock heads. The mild cams you listed will still work with the aftermarket heads, provided the springs those heads come with aren't too stiff for those cams.
Really in short, there are thousands of parts combos that can go together in any one engine that will work, you'll just see different results from the different combinations. Some work better than others, but mostly they'll all work to different levels of power output. What you want to try and avoid are radically different combos, such as a motor with low compression and a huge cam added to a big single plane intake like a Vic Jr. Do something like this in an automatic trans car with 2.75-3.00 gearing with a big DP carb and it's guaranteed to be a dog. Some combos work better than others, but they'll all work, provided some of the parts aren't designed for extreme high rpm performance.
First thing you want to do is ask yourself what you want to do with the car. Street/strip, commuter... From what your posting it looks to me like you want a car that is a cruiser but can drive it daily if you need to. If you're on a budget you might want to look for a roller 302 shortblock from your local craigslist. Prefebly 87-92 since they come with forged pistons. These could be had for 2-300 with under 100k miles and would be good for another 100k. Add some good heads like edelbrock, afr, trickflow. As for a cam, somewhere in the 220-225 duration at .050 with 110 lobe seperation. There are alot of good deals out there if you look for them that could save you a good chunk of change.
So I've decided on (and purchased) a few items so far: Performer RPM intake Edelbrock 600cfm Performer carb Performer Plus cam MSD Pro-billet ready to run distributor Hooker headers (came with the car) I jumped the gun and boughtvthe E-Street heads but it was too much for my budget - I'd have needed too many other parts to get them to run well plus I broke my bank so I'm returning them. They were niiiiiiice though, I'll be going that route in the hopefully near future. For now though I'm porting the heads I have - was thinking of getting 289 or gt-40 heads but again, $$$ - and getting new springs/pushrods. Crossing my fingers everything works out - frankly at this pointbid prefer it to just *work*.