Hasegawa has never and probably will never make a two seater for YF/VF-19 as it's not official. Two seater VF-19 only exists in VF Master File.
Obviously it needs some work on the canopy area. The good thing for Hasegawa 1/72 VF-19 kit is that it comes as a full size two seater, and it comes with second seat and pilots. that alone saves me a lot of work. I used a 1/72 F/A-18F canopy for this mod. The canopy was rather long. I ended up extending the rear pilot tub a fair bit. Despite sanding off some of the base of the canopy, it's still too wide for the VF-19 body. I have to add 1mm strip on both side of the body and some putty for the aft section. I suspect a 1/72 SU-27UB canopy would be a better fit. It will also gives a more prominent raised body style. Anyway, I've got to make do with what I have and it turns out not too bad.