I would go with the RX-V1400 by virtue of the YPAO room acoustic calibration function. And compared to the other receivers on your list, the 1400 probably has the best amp section.

The sound quality differences between midlevel receivers in my listenings is minimal compared to differences between speakers and acoustic environments. I've not tried the YPAO feature for myself, but others on this board who've tried it say it's made a huge improvement, and using a parametric equalizer (the YPAO basically is a parametric EQ, only it calibrates the settings automatically) for subwoofer equalization made a critical difference with my system.

I currently use a RX-V800 with my Paradigm Studio v.2 setup and it works great. My setup is a Studio 40/Studio CC/Studio 20 5.1 configuration. Personally, I prefer using direct firing speakers for the surrounds, but unless you got a large room, another pair of Studio 40s might be too big for surround use. Just so you know, the Studio 20s timbre match very well with the 40s, and when mated together the side imaging and soundstage with surround music sounds absolutely amazing.

If you choose to use direct firing surrounds rather than dipoles, the best configuration that I've tried is to position the surrounds slightly behind the listening position (110 degrees offcenter) with the speakers pointed directly towards one another and elevated at least one foot above ear level. This imparts a little bit of diffusion for ambient cues, while maintaining the strong imaging with directional cues. It's also the configuration that Dolby recommends for systems that are used for both movies and surround music.

I would be very surprised if the 1400 costs the same as the others on your list (except for maybe the Onkyo) because its list price is higher. You might be able to find a dealer willing to bargain a 1400 down to around $600, but keep in mind that the prices you see on the internet are from unauthorized dealers. Yamaha's RX-V series is not authorized for sale through mail order, and if you buy through an unauthorized vendor, you lose the warranty support and Yamaha is very strict about enforcing this.