An island bed without it being inside a side-protruding slide out is a rare find these days. Being only 26 feet over-all length is even harder to find.
I don't like a slide out located above or behind the rear axle because of the issues with weight distribution. I feel a centered walk-around queen bed without a rear slide out makes for an ideal bedroom in a class B+/C.
* This post was
edited 06/24/21 08:00am by ron.dittmer *
You generally won't find an island bed on shorter models because it would require having the rear wheel wells in the walkway around the bed, which means either having a decidedly not flat floor there or having the whole floor raised up rather higher than usual.
A few companies offer twin bed arrangements on shorter units, with a center walkway between the two beds. Possibly that could be an alternative that would work for you; possibly not. (Some further have available a filler bit available to convert the twin beds to a huge king bed with no walkway.)
If you would want one with a pop out then maybe a Four Winds 26 B at 27.5 ft
Looking for used you might try the Rental Market they are a lot cheaper and well maintained, over 130 members here have bought Former Rentals and are happy with their purchase.