Ibanez is fine brand,I'm not a fan of it tho but it's ok.
Neck through,it gives nice sustain,that's true but it's not main factor in sustain topic,
there is bridge,pickups,body,strings,gear and of course,your hands.
I can't suggest you Ibanez model since I really don't know that much about it,
I have one old Ibanez,from 80s I think,haven't touched it in more than 8 year
But since you're beginner I hope many models will fit you nicely,
latter on you'll see what are you looking for in smaller details.

Let me know if you need anything else,and practice hard.
Edit:just noticed this is your No 1 post,welcome to GMC.