To my understanding,
-VF-1 means the plane
-S or J type means different head (S is the head with 4 laser canons, J is the dual canons, A is the single canon head, D it will depend)
-DYRL and TV version means different color scheme, basically hikaru TV version is the white with red stripes, DYRL is the white/red/black with skull markings
-Hikaru means red color scheme, Foker means yellow/black, etc
The latest releases of Hikaru's VF-1 that include the optional display seat and side covers are probably the easiest and cheapest 1/60 version 2 models to obtain today. You will have the choice between VF-1J Hikaru TV version and VF-1S DYRL Movie version Hikaru
I live in Europe, and I usually recommend Nippon Yasan and Anime Export online shops. For the USA, I usually read good reviews from Hobby Link Japan.
Regards