from what I have seen - the ones that are setup specifically for USB recording look beyond shit sound quality wise, and while most people think vinyl sound is shit anyway, so these products sell, I adore the sound of vinyl and for me using one of those to record your vinyl to audio is kinda defeating the purpose of the vinyl. I think a lot of the 'DJ interface' style soundcard units have inputs specifically for phono now that will boost the input.
I have a Clearaudio Bluemotion (now currently in storage due to my young kids breaking the cartridge :p - but when they are old enough to not damage a turntable I shall bring her back out) -
the sound is to me very nice - great 'roundness' and detail in elements which are traditionally problematic at 44,100hz (Hi Hats, Crashes, snares etc.) anyway as usual I'm wandering off topic :p -
that costs about 1000 euro or so, which may be too much, but a lot of people say these are a great turntable - the Pro-Ject ones:
http://www.switched.com/2010/10/25/the- ... 400-vinyl/
or a REGA RP1 which are roughly the same price:
http://www.rega.co.uk/html/RP1.htm
I used a small interface that just took in the RCA/phono plugs and added a small boost and sent to usb, unfortunately I can't find it at the minute and am not sure who the manufacturer was. I only managed to copy about 5 slabs of vinyl to my PC as 24-bit 48khz WAVs, which I then converted to 320kps LAMEs also, before my kids broke the cartridge, but the sound was really very very nice.
anyway that's some suggestions, hope it helps