Fish mojo, we have an older 2007 Adventurer 90FWS on an 8' truck bed. They re-introduced the exact same floor plan, only as mirror image, in their 2019 50th anniversary edition truck camper and called it the 901SB ... the model you've referenced. It features lots of up-to-date materials, electronics and extras being a special edition. Appears they went all out. Google Adventurer 90FWS for lots of information, videos etc. on the basic "bones" of the 901SB.
We thought this "repeat performance" was a real testament to AMLRV who got it right the first time and re-used what was once one of their more popular floorplans. The 901SB is also a non-slide unit like ours and we love the layout with mid bath; full basement; storage areas; the camper quality is good and it offers a north south bed ... something we've really come to appreciate since the east/west bed set up in our first RV - a Class C.
You can not look out the rear door of our Adventurer 90FWS though ... both upper and lower windows have "frosted glass' and we actually prefer it that way. Good privacy but still lots of natural light coming in too. It is a bit of a climb up but we have a series of "stairs" we've perfected using an RV step and a couple of aluminum work platforms.
Our 90FWS is heavy and long. I can't believe they say it's OK to put it in anything shorter than an 8 foot box. I certainly wouldn't. I'd really want to check that out beforehand.
Regardless, I'd also consider stepping up to a full ton truck with the 901SB. Our 3/4 ton 2001 diesel F-250 SuperCab with 8' box handles it fine but if you go strictly by the numbers, the full one ton trucks give you more capacity (wiggle room) on paper. SRW is fine ... you don't need a dually unless you want the extra stability and safety "insurance".
I just posted a couple of pics with our unit mounted in one of the other threads on "7.3 trucks" if you want to see what it looks like on a 8' bed.
Pics of our F250 7.3 diesel setup with our Adventurer 90FWS Happy to provide other insights ... just ask.
2007 Adventurer 90fws Truck Camper
2001 FORD F250 SuperCab; 8' box; 4x4, 7.3l diesel, rear Sumo Springs