What cam for a 289

I'm restoring a '67 Coupe with a 289 (NOT Hi-Pro). I'm looking to get about 400 HP out of it. It won't be a daily driver but I'm not looking to build it for racing really either. I'm overhauling the engine this winter and have been looking at kits. (I've decided to ask 3 questions here rather than post 3 seperate times)...

QUESTION #1

What cam do you guys recommed? I have done limited engine work and am no expert. One of the best sites I went to so far has 4 choices:

Stock (no thanks)
Hi Comp
RV (what the hell is RV?)
Hi Comp - RV

Hi Comp - RV is the most expensive at just under 300 bucks and I assume it's their beefiest. I want it to sound badass at idle but I don't want it to sound like it's ready to die either (loping).

BTW: I already have Dual exhaust w/headers (cheap ones but new), 4 bbl edelbrock intake and Holly carb (new), 351 W heads, C4 tranny (not original - tag # checks out to be a '73) that I'm having rebuilt, and a 9 inch rear axle.

QUESTION #2

How do I tell which model of Holly I have? Is there a stamped # I can reference? Where is it?

QUESTION #3

How do I tell what spline number my drive train has? Count them? Then what number is recommeded for 400 plus HP (28?).

I think I can make some pretty good guesses at these questions but I'd like input. Thanks.