The best monitor under 1500

I'd grab the KEF LS50s. Stereophile Product of the Year for a reason. A great sounding speaker. Compact, and there is a plug for the rear port in case you need them against a wall.

For a traditional set-up, I would recommend the Ascend Acoustic Sierra 1 . There is a pair here on Audiogon for $750 . These speakers have bamboo cabinets, which tend to be particularly immune from vibrations.

You could also go the powered speaker route. These speakers look interesting ... Emotiva Airmotiv 6 .

Rich

Spendor 3/5r2!

Since this is RV, why don't you go for the Pioneer SP-BS22-LR and save some?
With experience I can say that if you keep them between 1-2 feet from the rear wall you will get pretty tight bass. Move them 4 feet from rear wall and the bass goes bye bye. But the overall experience with this speaker has been amazing. So highly recommended.

KEF 50 is a great rock speaker, but IMHO way too forward for Classical .