So I popped into my favourite local music store Andertons to have a look at some of these bits of kit in the flesh, and got chatting to one of the employees there. He managed to convince me that if I wanted an interface I should focus on getting a good interface with decent pre-amps. One of the options he showed me was the Presonus 22VSL. So I went away to investigate this and that introduced me to Presonus Studio One which comes with a free "Prime" version that seems to do everything I want!
So I downloaded it, installed it and within a few minutes was happily loading, editing and (most importantly) saving MIDI files! I have a solution.
Then I got to thinking, the Pod HD300 is an audio interface and guitar amp, and the VE20 is a vocal preamp, so so long as I can get a clean line through the HD300 I should be able to record guitars and vocals just fine through that (or at least until I know better what I'm doing).
As an experiment I decided to try and backup all my recordings on the VF08 through the HD300 in to Studio One. They are all rubbish so I just recorded a mixdown rather than saving each individual track (except for one song which was the one I had put most effort into). Anyway, the results were great. The only limitation is that the HD300 input has to be mono, but everything I had recorded was mono anyway so that wasn't really a problem.
So for now, I have an interface and I have a DAW, total additional cost £0! I can actually get back to my original aim of doing some music. And here for your listening pleasure is a fixed version of piano and strings: