Add on an iPad and the world of Software Synths is easily accessed,
OP said he'd "prefer a hardware option over a MIDI controller and PC setup." An iPad setup is closer to the latter. Yes, I did say he'd need an iPad for synth editing on the VR09, but at least it's only needed for editing, it's not subsequently needed for actually playing the sounds or doing simple real-time manipulations. (And yes, I'd rather have avoided even that, but getting an easily editable analog-style synth and a decent drawbar organ in a single board with a $1500 budget is going to require compromise... I'm just trying to minimize those compromises, rather than adding more.)
Sure, if he's willing to use an iPad for the synth functions--or, for that matter, the organ functions, with the excellent B-3X and VB3m apps--then you open up the possibility of other keyboards. In fact, at that point, arguably almost ANY keyboard can work. But we're no longer addressing his desire to try to do this in hardware (while likely also impacting ergonomics and tactile control). Though if he gives up on that, then of course, a largely (or entirely) computer or iPad based system could be another way to go.
in fact Korg have very many Synth Apps many of which I have used with the 700.
The Korg synth apps work just as well on other keyboards as they do on a Korg. In fact, I'd say they work
better on other keyboards (from Korg and others) than they would on the PA700, because of the PA700's lack of assignable knobs/sliders, and clumsy way of selecting patches from externally attached devices.
Korg currently are the synth kings with about 30 being shiwn on their websites and hence there are very many synth sounds already in a Korg Pa
There is no correlation between how many synths Korg makes, and the quantity (or type) of synth sounds that are in a PA. The PA's synth sounds are simply rompler-style samples, and very different from what Korg does in their analog and VA synth gear.
and editing them is pretty easy.
Editing most (not even all, but just most) of the common synth parameters on a PA700 sound is covered on pages 411-445 of the manual. It's very flexible, but I would by no means call that easy for a novice. It would be very hard to "learn synthesis" from that. There's tons of navigation to different screens with single-knob numerical data entry and little context.
Also the classic Triton sounds are readily available and install very easily on any Korg Pa, yes the sample size is cut down but they are still mightily impressive when installed on a Pa700
The Triton sounds are not particularly applicable to what the OP is talking about. But as an aside, the sample sizes are not cut down. The Triton download includes no samples whatsoever... it repurposes similar sounding samples that are already in the PA. BTW, since (IIRC) you no longer have your PA700, if you miss those Triton sounds, the full Triton sound set is available as a Mac/PC VST (including even the expansion packs, and I think all with their actual original sample wave data), and a "best of" Triton subset is available on the iPad as an add-on purchase for Korg Module. Lastly, just getting back to one point from your previous post...
inbuilt style play auto accompaniment features and over 40 free additional Style packs available for free from Korg.
Styles/auto-accompaniment is not of much use for prog rock, with its typical use of shifting and/or odd time signatures, specifically arranged counterpoints, changing tempos, widely varying instrumentation, etc. It is unusual among popular genres in that songs typically do NOT generally follow a formula that lends itself to the creation of single backing rhythmic accompaniement that will work through the entire song.
Anyway, I do really like my PA1000, it's just not what I'd suggest for what the OP said are his priorities.