Yeah, I agree with Ninja...stay away from the Sunfire. From what you've posted it seems that budget is not a concern, neither is WAF factor considering the different sizes of the subwoofers you mentioned. All of this makes it extremely hard to make a decision as to which sub(s) would better suit your needs. But for a best bang for the buck, it really is hard to beat HSU or SVS. Both will give you enough spl to blow the clothes right off of your bodies.
Sorry for the analogy but it seems like everybody is doing that these days.
Remember the servo-drive subs (such as Velodynes HGS and DD series) will give you a different kind of base than the other non-servo type subs (such as HSU and SVS). Because servo-drive subs contain very little distortion in the full bass spectrum, when you get below 20-25 HZ you will feel it more (i.e. pound you in the chest). Whereas, because SVS and HSU have typically more distortion (mind you in the lowest octave where it matters most) it will tend to have a more audible impact (pound to the head) rather than a subsonic impact of the Velodyne. Thats not to say that the Velodyne is better than the SVS or HSU, but rather there is a different kind of bass. Most people are used to hearing some distortion in their bass since they're not too many subs out there that can actually produce distortionless bass. This is the reason why a lot of first time servo sub buyers actually have to turn up their subwoofer level because there isn't anything audible (because there's not supposed to be according to the recording engineer). Indeed, some frist time servo sub owners actually return the sub complaining that the sub sucks for this reason. In comparison the audibility that we here in typical subs (such as the SVS and HSU) is the fundamental frequency plus and distortion. This is the bass that we are all used to, and these subs (SVS and HSU) give us an INCREDIBLE abundance of it (i.e. very high spl's). So to reiterate, unless you already own a servo-based sub, and are used to the sound, (and the size of the sub is not a concern) I think for the money either SVS or HSU is the better way to go. Afterall, if you're going after perfection, you may find you don't like it, especially for the steep added expensive. It may very well not be worth it. But of course that is up to you. BTW, I wouldn't worry about the distortion for music - from 30-35Hz on up both HSU and SVS have minimal distortion (in fact, probably inaudible). Hope this helps. Good Luck.