IMHO the main reasons for buying a high end Ibanez are:
- the neck (thin, wide, flat, strong, smooth)
the pups (Dimarzio)
The Jem is the original, but a esthetically bit much for some, who prefer a more subdued look. For those players a high end RG is a good alternative.
- the first years of Jem have the Edge ('whale tail Floyd')
the middle ~10 years have the LoPro (set the standard in the business, better than a real Floyd, I've seen idiots replace LoPro 's with other FR copies, claiming they were better, but IMHO this is due to poor knowledge and bad set-up)
the last few years have the Edge Pro ( ++ even lower profile, ++ intonation chips, -- no locking studs)
Pups in order of appearance:
- PAF Pro (LNG DY, FP, etc.)
Evolutions (90HAM, 10th, 7VWH, BSB,..)
the Breed (DNA, DBK, BRMR)
for detailed info (for which suits your needs most)
As for the necks they have become slightly thinner over the years, thinnest are the HAM, DNA & DBK (apart from the VDY and rare other Wizards) but IIRC the latest versions (7VBL, BRMR) are slightly bigger again, but not as big as the original LNG/DY. This is something you need to assess yourself. Biggest change as mentioned is the transition from full-cut heel to all access neck joint and the scalloping.
the 555 is a korean RG with EVO's and a monkey grip
My advice, if you don't want to spend much, get a NOS DBK or VBL, if you can find one, or save up for a new BRMR. Otherwise get a 2nd hand BSB or even DBK.
If you have the cash, get a 90HAM (~1500EUR) or 10TH (~2000EUR)
Be very careful with auctioned 7VWH's. Too many bad copies floating around a n00b could be fooled.