If I wanted to upgrade my stock Yamaha neck, what options do I have/what fits the body)?

Had an Ibanez (forgot the model) that I bought new for just under $1000 back in -91.
It had a really thin neck and was a dream to play on.

Some pics of my yamaha RGZ612 (24 frets):

Yamaha RGZ612 w IronGear Steam Hammer Bridge PU
Zoom 505.

Just an happy amature playing for the love of it.
I think you're talking about the Wizard neck with the Ibanez? you can probably pick up a WizardII or III on ebay for under £100 GBP. iirc they have a 53mm heel and are 25.5 scale 24 fret so if the neck pocket is right you should be fine (might have to fill the holes and redrill though)