I would go with something that actually has a soundcard build in. It is much more convenient to use.
Our suggested beginner controllers at the moment are:
– reloop Beatmix 2 and 4
– Numark Mixtrack Pro and Pro II
– Pioneer DDJ-SB
The Reloop ad Numarks will work best with VDJ, however the Beatmix 4 comes with full Serato DJ already, which will save you upgrade costs.
As for VDJ usage you will need a VDJ version that supports external controllers. Some of the controllers come with a “light” Version of VDJ, but if you want to continue to use it you might factor in the 299 bucks for the Pro Version of VDJ, which might sound steep, but it does come with free lifetime upgrade support.