Update: my (aging) case can only support up to 11.4" (289mm) in length, so that limits me to one option from the
RX 9070 XT list, five options from the
RX 9070 list, and (worst comes to worst, but not too likely) a whopping 17 (theoretical) options from the (gasp)
RTX 5070 list. I'll swallow my pride if I actually can't find a 9070 XT or 9070 that does the trick (as any of those choices would be significant upgrades over my 6700 XT), but from what I've been hearing, I should be in luck for either the 9070 XT or the 9070 re: inventory choices at MicroCenter on Thursday (I was actually @ MC earlier today, and was able to talk to a manager at their Information Bar).
That, along with my screen upgrade coming in this Friday, should tide me over in the short term (I'm planning/budgeting for a new rig build later this year -- possibly summer or BF/holiday time, not entirely sure yet).