Do NOT use lowering blocks unless you want to rub the wiring under the rear fender. Your bike is already lowered an inch in the rear....a 12" shock. Stock is 13". If you have any mechanical skills, installing a Legend system takes about 2 hours, so $600 for installation seems outrageous to me unless they are going to route the switch wiring internally on the handlebars. If you have a jack stand...something like the J&S jack, Bulldog, etc, and basic tools like sockets, torx drivers, and a few wrenches, it's an easy job to install them.
I've had Legends on two different bikes that had stock height shocks (13"). I have a 29" inseam on a good day (I'm shrinking). The only time I needed the shocks to be lowered all the way down was when I was parking the bike (backing it up, particularly). If you're in town and going from light to light, just pump the shocks up about 1.5" and the ride will be fine, plus you'll be able to get a good foothold for all but extremely unusual situations, then pump them up to the desired ride quality for the load on the bike when you get out on the open road. The nice thing about the Legends is that the ride in infinitely adjustable on the fly. I would not recommend riding the bike with them lowered all the way...it won't hurt anything, but the ride will NOT be good. Enough air to keep the shock from bottoming out is where you want the shock to be.
With a 32" inseam, I would never have needed Legends. The Legends drop the bike 3.25" on a bike with 13" shocks.
If I went to a normal shock, I'd look hard at Bitubos, or the higher end Progressives. Bitubos are adjustable in three different ways...rebound damping, spring tension (sag), and compression damping. One of the best shocks out there, bar none. Several people here ride on Bitubos and I've yet to hear a single person complain once they are set up properly. They come in a 300mm (12") version and 330mm (13") version. There are other good shocks out there as well, but IMO, there are none any BETTER.
BTW...the front forks on a HD....ANY HD...suck as much or worse than the rear suspension, so I'd consider upgrading that end as well.