IMTU, Skiltaire, at least come in two flavors, aquatic and arboreal - the aquatic are fairly otter-ish in behavior/psychology, while the arboreal are morelike pine martens.
Their ship architecture/technology was initially heavily influenced by Zhodani and Imperial designs, but by the time they're starting to play interstellar politics themselves, they tend to include swimming pools in their slightly larger (50% more space allocated - diplomatic ships are just shy of being yachts in some respects) lounges and lots of 'jungle gym' climbing plants. A transparent emergency cover on the pool can seal it up from the bridge before maneuvers or combat - any situation where local gravity might go haywire or inertial compensators might cause slosh.
I figure as far as uplift's concerned, it'd really depend mostly on what they're being uplifted for. River otters are fairly adaptable to land, and would be a nice marshland/deep woods/river scout and colonization race. Uplift, modify, indoctrinate, drop a viable mass-cloned population on a hospitable world behind enemy lines and pull a whole C.J. Cherryh's "40,000 in Gehenna" scenario.
You've installed a sleeper 'culture' favorable to yours behind enemy lines that by the time they're discovered, they're established.
Fishers (big arboreal weasels) might be even better for this, depending on the planet's plantlife. Colonize the upper reaches of the forest canopy, infiltrate areas of a world that your competitor might not even be looking at.