The Onkyo looks like a pretty good choice. Lots of good user reviews.
I think the Yamaha AS301 is a better choice, but it's only available in silver and like the 3020 speakers, it's in-store only purchase. Also, it is taller than the Onkyo, so I don't know if you'd prefer something not so tall and in black. It has got a built in DAC though, so as long as you have optical out on your motherboard, then no need to use the onboard audio or bother with a sound card, or a separate DAC for that matter.
Whatever you do; if you do go for something that is only available in-store, make sure they have it in stock at your nearest store before you go. In-store purchases are not always available at every store, but they might be able to get them delivered to your nearest store if you give them a call.
If your nearest store doesn't have the 3020's or can't get in for you, then there are other good options; such as the 2020i, which can be bought direct from Q Acoustics website for £90. They are still a great choice. Some guy posted in the hifi section said that he went to Richer Sounds to listen to the 3050 floor standing speakers, but decided to stick with his 2020i's as he preferred their sound. Goes to show, that a new more expensive range is not always an improvement that can justify the greater cost over the previous range.