since this is a Forest River forum, are you looking for a FR recommendation or any recommended rear slide brand?
since not many rear slides are made, your choices are very limited.
Outback seems to have the most choices of rear slide floorplans and many have a king bed.
as far as i know, FR makes only about 3 rear slide floorplans. i'd recommend you look at the Surveyor 235. has the length you want and big bunks, with a king bed slide.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC