The 3313 won't have a better amp section than the XPA-5, so I'd choose the setup with the amp for speakers like that. If you get a lower Denon with pre-outs, you could still have a solid setup though, since you could still add an amp. I don't have experience with the Verus line, but the Grand towers are listed as 92dB sensitive and 6 Ohm, so a receiver might be able to handle them fine if you don't have a massive room and depending on your listening levels. Though I don't think SQ will be a significant difference between the two, just in terms of amplification, I don't think the Denon is going to give you the same performance for the price.