On a SR SOA, longer slip shafts are a must. From what I've heard from people's experiences with Downey,... buy from someone else, there's several out there,... MAF, SOR, + a few others.
IMHO it's all about preference,... I've had both, and am going back to SUF (shackles up front), within the next couple of days w/my spring over. The few things I didn't like about the shackle reversal were its tendency to "squat" during braking, and gearing down hills, push my ds wheel into my stock steering components (not stock anymore though), plus I always was leary of my driveshaft separating (though it never did). I didn't like the stock configuration either when I was first getting started (a whole year & 1/2), granted, everything was original then, and frankly, worn out.
You're always going to have some play in a Cruiser's steering whether it's the shackles are reversed or not. The reversal just masks some of the play in suspension travel. The only way to alleviate the play would be to add a panhard bar to the front suspension.