Just a few comments to follow on from everyone else:
The deLuxe/DeLuxe reefer is more of a classic 80s-90s body style and the schemes they've released to date reflect that. From memory it's a hi-cube 9.5' tall container too. It's a farly standard sheet and post (smooth side) container and you can see some faint panel lines on the model.
The COSCO scheme comes from this era - I haven't seen the panda around much in the last 10 years or so and seems to have gone out with the COSCO / China Shipping reorganisation:http://www.matts-place.com/intermodal/part1/ref/cbhu2903810.jpg
At least the Pacer Stacktrain Thrall 53' well car in the photo puts that COSCO scheme into the "modern" era (post 2001).
From the early to mid 2000s, the sidewalls seem to be more of a composite side (my description) where the panels are more pronounced (or the posts are recessed?) - perhaps with improved insulation:http://www.matts-place.com/intermodal/part1/ref/apru5771692.jpg
From memory I saw and shot my first of this style with @NSEGeorge
down in Long Beach in 2003 - a K-Line one in the white scheme.
Most of this style onwards seem to be white containers.
The more recent version of this body style has a much more pronounced bottom base rail:http://www.matts-place.com/intermodal/part1/ref/mmau1038643.jpg
Here's a site with lots of photos for help with era and paint schemes:http://www.matts-place.com/intermodal/part1/refrig.htm
DeLuxe did do the silver K-Line reefer - here's a shot with one of the reefer power packs referenced earlier. K-Line and Sealand had good fleets of these, photos can be rare to find though. Sealand are typically open framed 20' containers.http://www.matts-place.com/intermodal/part1/ref/klfu5957018.jpg
Generally speaking to the cans you've shown, the Maruba is fairly uncommon in intermodal service. I think the Seaco scheme is also an older one - they merged with GE and GE-Seaco markings are fairly common although Matt's page has quite a few modern cans in lease service with just Seaco markings. The Hapag-Lloyd scheme appears an older one too.
The Maersk-Sealand scheme is the most modern - they merged in July 1999 and the first 40' reefer appeared in this new scheme in January 2000. Still seen today, even though Maersk has dropped the Sealand name from use.
I must say though, from my observations, the 20' reefer is a relatively rare intermodal load. I don't know the reasons why, but you just don't see them much on the international container trains.
Whilst the N scale world has seen some good developments in ISO dry containers in recent years (Kato, Rolland, DeLuxe etc), the reefers haven't kept up and the two models you show are the only two currently available. These two models, and the paint schemes previously done by deLuxe (plast bags) and DeLuxe (blister packs), are likely all that will be available for some time.
They are great models though. When they were first released I followed this article on how to dress them up and detail them a bit - the techniques work just as well in N:http://original.trainlife.com/magazines/pages/288/21408/may-1999-page-6
Hope this helps!