Any surround sound receiver you buy will have multiple HDMI inputs.
A DVD/HTS may not have more than one HDMI input so you don't lose the HDMI input on the TV when you use ARC to get audio from the TV to the HTS.
If your TV will output in surround sound via optical the only downside is that is you have a source that outputs lossless audio (like blueray discs) you won't get the better audio quality.
It does not have any HDMI inputs, so stay clear from it (and others on same league). While the TV might return audio thru the ARC channel, it's not clear whether it will do for all sound (and not just for TV aerial signal), or whether this signal will be 5.1.