Keep in mind that you are talking about two different, but related, things. The spring rate must be suitable for carrying the weight.
And, the damping slows the movement of the suspension. There are two or three types of damping. Rebound damping regulates the speed the shock will extend to its normal length after being compressed. The stock shock has an adjustment for this, as does the Ricor shock. Compression damping regulates the speed the shock shortens when you go over a bump or use the brakes. This can be split into high velocity compression (speed the damper moves, not the speed the bike is going) such as hitting a pothole, and low velocity compression such as using the brakes. Only shocks priced higher than the Ricor have compression damping adjustments.
The coil-over shock combines both actions in one package, the spring and the damper. Ricor is one of several sources for a superior shock, and like most (not all) offer a choice of springs to suit the weight carries. What does Ricor say about your 350+# on their spring rated for 271# - 330#? Can they install a stiffer spring? RaceTech can put a stiffer spring on the original shock and also upgrade the damping, local suspension shops can change the spring, and other aftermarket shocks may offer a more suitable combination. Ricor might be the most for the money, but if it isn't suitable for your use, then it won't work well for you.
Here's the Elka shock
, $800 without remote preload, maybe less with only two way compression damping, and you would need to specify the weight carried to get the right spring.
For the front, put in springs suitable for your loaded riding weight, then see if the front damping is OK for you. Ricor's Intiminator damping valves work well. Luggage and a passenger don't put weight on the front, so not a concern here.