all of Asus' cards support Dolby Headphone, so no worries there
wrt the HDMI question, your monitor has HDMI "out", or HDMI "in", there is a distinctive difference (and I've yet to encounter a PC monitor with ANY video output, especially HDMI)
I agree with Alydon: what are you hooking up to this? (you need a solid answer, at least for yourself, or else you may very well end up buying nothing, or buying something loaded with features for "what if" support
)
as far as krosenqu's comments regarding Creative, I disagree, their customer service is about average (honestly, as someone who's dealt with MANY levels of VARIOUS types of customer service both in a professional and personal fashion, I'm telling you, FAR worse exists, and "far better" is quite subjective (imho only one or two companies have ever really given, imho, "good" customer service to me)), and their product quality is more than satisfactory
driver updates don't need to happen weekly, if it works, don't screw with it (and anyone who thinks otherwise likely has never worked with software for a living, if your features are working, and you have no compatability issues or major problems, LEAVE IT BE, lest you create some of those problems), not to mention that Creative does offer driver updates as required (i.e: if a feature is broken, they generally work to resolve it on their time table, which is apparently not "good enough" for many users, but what are you gonna do?), and overall makes a solid product imho
for a pure stereo or multi-ch source, I'd have no issues suggesting them alongside Asus or one of the smaller companies (namely Auzen and HT Omega)
now as far as "I need to upgrade because some head-fi'er said I have bad equipment", thats pretty silly imho, would you trash your car and buy a new one purely because it isn't as good as mine? would you sell your house and buy a new one, purely because mine is bigger? (I've sadly seen people do the later quite often, or at least suggest it quite seriously to others)
as far as "could I get both", I would have to ask, why in the hell would you spend nearly $500 on audio cards for less than $250 of headphones? (seriously, you should stop and evaluate this spending from a logical perspective) also, why would you deal with the hastle of having both installed constantly? (and somewhat more importantly, does your computer even have enough expansion slots for it?)
honestly I would take the HDAV if Blu-ray and HD audio is "big" for you (assuming you're using an internal drive on the computer to watch the movies), otherwise, I'd save my money and go with something like the X-Fi Forte or HT Omega Claro Halo (what a mouthful, sheesh), if you simply need a stereo or multi-ch source for your headphones/speakers