I went with the more economical Monroe shocks on my Son's advice. Several years ago he did some tests to failure of various shocks at his community College Automotive class, using an MTS industrial shock absorber testing device, and found that Monroe shocks survived much better than most other brands, which failed catastrophically in many cases. Timely advice - and it was good to finally get some benefit from all that tuition we'd been paying!
Still, I was cautious and tried researching the various models on several websites, as well as calling several of the local Monroe dealers for advice. This narrowed my range of choices down to 5 models.
Still, being suspicious of the seemingly conflicting results, I called Monroe Technical support directly several times, and they advised that since I had a heavy 6400 pound GVW maxi conversion van with a HD (heavy duty) rear suspension, that the advice of the Monroe dealers and the various websites, including Monroe's own website, wasn't all that good in my case!
They said that the shocks that were recommended to me by the dealers and web sites were either too light duty, which would have ridden spongy and would have blown out prematurely, or were too stiff and would have blown out my back! (I've had back surgeries.)
The Tech Support folks recommended the Reflex shock, Monroe model number 911091, as the best fit for my application, so here they are!

They are certainly a big shock too; slightly larger than the Sears Roadhandler Gas shocks that were on the van to start with.
The ride is quite tolerable to my touchy back, and the recovery response appears to be well damped to me, though I also have rebuilt the entire rear suspension, adding heavier leaf springs, (originally had 1980 lb 5-leaf, went to 2770 lb 6-leaf) added a front swaybar, and installed rear Timbren SES Aeon DVR150 Air Springs, which act much like helper springs and rear swaybars when they come in contact with the rear axles.

You can see one of the Monroe Shocks in front of the Timbren Air Spring in that picture...
I've put off replacing the front Sears Roadhandler shocks (which appear to still be OK) till I decide what if any work I want to do to the front suspension. The coil springs are sagging up front, though I like the look well enough to either leave it as is or replace the springs then convert to drop spindles. With the sagging coil springs, it *may* be necessary to specify a shock with a different stroke length.
The nice thing is that the Monroe factory is only about 20 miles from my house, so it's a local call for me to discuss any issues with them.