If ever there was a bass to play around with mods, this is it. If you can fit a pre into an Altoids lid, you can certainly pull off a preamp transplant.
I’d also suggest the lightest gauge DR Pure Blues six string set. Bassstringsonline.com.
My fear with swapping out the systems is that I'd have to drill another hole for the extra pot. And if I don't like it I can't go backwards. The new preamp comes with master volume, blender pot, and bass/mid/treble pots (5 in all). The Ibanez comes with two volumes, master tone and a bass boost. I'll probably play with it stock for awhile. I won't mod it for at lest the 45 day return period.
I like DR Pure Blues. I've got them on my Fender Jazz 5er and had them on my BTB and Yamaha 605. The BTB and 605 now have D'Addario NYXL's and I think I like those better on those basses. But the NYXL's are a little pricey so when I change I'll probably do the Pure Blues for this bass.