there are two schools of forced induction cams, one is the old school of very small overlap and more exhaust opening than intake opening, the other one is running a cam that is close to a naturally aspirated cam, the cam closer to the NA cam will have less boost becaust of less restriction, and a bit more blowby, but will make almost the same power as the blower grind does (with the same pulleys) but the engine caracteristics will resemble a NA engine more, but if you run the same boost level, although you have to overdrive the blower more to run the same boost with a NA cam than with a blower specific, you will make more power from the NA style. (I am guessing thats why he specified the 110 degeree lobe seperation, for a BBC with a relatively small blower)
if i were you i would go with the 110 LS cam and be happy with sound and idle you were asking for, i mean the guy specified a cam for what you told him you wanted. why second guess that, if you wanted max power and big lobe seoeration he propably would have said somthing different.
just remember that you are building a pro STREET car, if you wanted max power you should build a totally different engine. starting with a 14-71 or 16-71 high helix cobelco blower, on a 5 inch borespacing DCRE 750 cui block and Dart Big chief heads. Not to mention the Enderle Buzzard catcher and methanol injection Hat.
Stick with what the expert said matched your demands, and dont try and sub-optimize every little choice, that way the final combo will be missmatched