A cam that has around 210 degreees intake, 220 degrees exhaust duration @ .050" with 112 lobe centers and around .450" lift max. should work well for most mild 400's and give good throttle response and reasonable fuel economy. If yours is originally a 4 bbl 400 you should have at least 10.5:1 compression ratio and you can bump the duration numbers up another 5 degrees (215/225), which is very close to the 068 cam (068 has about .410" lift).
I think the Edelbrock cam mentioned is a copy of the 041 cam that has 230/240 degrees and .470" lift, too much for most and the heads have to be set up for this much lift.
For regular street use, make sure that the distributer has been properly recurved. The advance curve should start at about 1200 rpm and be all in by 2500 rpm. Rough timing numbers would be 12-14 degrees initial and 36 degrees total, so the mechanical advance needs to have 22-24 degrees at the crank or 11-12 degrees at the distributer. Vacuum advance should start at 6" of vacuum and be all in at 12", with about 12 degrees crank advance. Remember this is a starting point and a good shop should be able to get this razor sharp... Listen for pinging very carefully!!!