Regarding the Icons vs BP51s... I like them both a lot. I trust and like ARB/OME as a brand, and I trust and like Slee even more. The BP51 is at the top of the food chain according to both (and well stocked at Slee), and I'm very happy with them on the 200. I have a later version of the shocks which do not make any noise whatsoever - they're unbelievably quiet in fact. They're great on the pavement and in slow off road, but by far where they shine the best is higher speed off road. They soak up bumps above 10mph ridiculously well and don't show any signs of fading or overheating when put through their paces, and I appreciate how OEM they look in the 200 combined with the SPC UCAs. It took a couple of adjustments of the rebound and compression to get them just right, which in my opinion is kind of a pain and you need tools for it, but now they're set they're amazing.
The Icons are more expensive, but they offer a far easier adjustment process and are more "exotic" which is good and bad. They make a little more noise and will likely require more maintenance, and they definitely look cooler and less stock. They were combined with Total Chaos UCAs and LCAs which have uniballs, and they definitely require more maintenance and will squeak and groan like a haunted pirate ship unless you keep up on the routine of cleaning and lubing them which isn't hard just time consuming. My favorite feature was the CDCV which allowed you to simply turn on a knob on the external reservoir to adjust the shocks' firmness on a scale of 1-10. I would have them cranked up to an 8 or so for driving around town, and they handled great without being harsh. When I'd air down off road, I'd adjust them softer depending on the terrain, and they'd be dialed in well for those conditions. The setup worked ridiculously well, and I have nothing bad to say about it.
I guess the easiest way to answer the question is would I build up a truck again using BP51s or Icons? The answer is yes

The biggest determining factors for me to decide which to go with would be price and support from an installer. The Icons are more expensive, and while I think Slee has installed them here and there, they are a big dealer for BP51s and have installed many kits on 200s. If it was the other way around and they were a big Icon dealer, I would have gone Icon. To me, getting the suspension installed, dialed and aligned correctly is every bit as important as choosing the right components.