Just flying it is illegal at the moment, as it has no certification, no permit, the CAA don't know what licence you need to fly it and as far as I can tell from G-INFO it isn't registered, either. The company that have built it hold no approvals, either CAA, EASA or whatever, so it's a long way from being legally able to fly, at least in UK airspace, and even further away from being able to be sold ready built.
Kit sales will be possible if the CAA agree to extend the conditions of the BMAAs Exposition from the 450kg microlight limit up to 600kg, and Parajet can get it through CS-VLA approval. My guess is that this will take maybe 6 months of work, if they get a clear run at it.
Then some form of licence will need to be created, as the current powered parachute licence is an NPPL microlight licence variation and only covers up to 450kg MTOW, I believe. It may be possible to extend the NPPL to a greater MTOW, but that then restricts operation to UK airspace.
AFAIK, a JAR SEP might not cover a powered parachute, although I am fairly sure that an old CAA PPL will, just as it does for flying microlights (one of those odd licence anomalies!)
As for making it legally IFR capable, then the answer is that it'd be near impossible. It will have to operate on a Permit to Fly, unless Parajet can get themselves EASA approved as a manufacturer of certified aircraft, a process that will be expensive and take a long time. If it operates on a Permit (as a kit built type), then it's restricted to day VFR only.
VP