Todd, the H/K would drive those just fine. Before making the move to separate components, I had three different H/K receivers driving my Paradigm Ref setup (40's in front, 20's in back and the CC). While not giving the performance of separates (hardly any receiver will), the H/K really does a bang up job. It's high current design belies the low wattage rating and will be a good match with those speakers because Paradigm's tend to be slightly forward in nature and the H/K gives off a nice lush, warm sound that mates really well. Fret not...it's a good choice.
Second that opinion. I was seriously considering the 40s with my 320 and did extensive auditioning at a dealer in Montreal that sold both Paradigm and HK. Ended up going with Triangle Titus 202s (and could not be happier) but you should do very well with the Studio 40 and 520 combo--especially if you care about 2 channel music.