You are right about JVC's DB711 unit. you do need a DAB aeriel as well.
the Kenwood KDC-W6031 is a very nice (and simple) unit which I had in my car for about 2 months. It's easy to use and the sound quality is there. the only niggle I had was using the tiny joystick on the right to skip through tracks. this can be fiddley on the move and sometimes you end up knocking it up or down instead of left and right. last month we were doing them for £149 as we got a stonking deal from our supplier.
Alpine's current range is their best yet (imo). The CDA-9855R being the one to go for. It's been the top selling headunit for several months now. Although a bit over £200 it's well worth it. The display is nice and clean and the glidetouch makes it quick and easy to skip though the menus (once you get use to it). If you really can't hold off to get the 9855 the 9853 is almost the same, but has a more basic display. All the alpines above the 9847 support ai-net which opens up loads of expansion options if you ever wanted to use them.
Be aware that a lot of new headunits are about to come onto the market so it might be worth holding onto your cash a bit longer to see if these units can be picked up cheaper
