The multimode isn't important enough to pass a up a good SR5 IMO. And like The Kid said, you can still find the rear elocker in SR5s too (not just Limiteds). If you aren't going to be wheeling it hard or driving in deep snow a lot, the elocker isn't going to make a huge difference anyways. And if you decide you want a locker later, you can always go aftermarket like I did (with ARBs).
I personally wouldn't spend money on an LSD for a wheeler. Lockers work a lot better on the rocks, but to each their own. Personally, I would only go the LSD route if it was a prerunner/baja style truck for cornering fast on loose surfaces. In the rocks, where you'll be lifting tires off the ground, the LSDs aren't worth the $$ IMO.
One advantage of the standard SR5 t-case (non-multimode, aka "J-shifter") is the 4wd shifting is manual (not a push-button) so there is just that much less to go wrong. There are a few days out of the year when the roads have patchy snow/ice where multimode would come in handy, but in those situations, I just shift between 2hi and 4hi as necessary. It's not a big deal.