The user's name is Koiflowers. She has photos of her garden tub to shower conversion posted under two topics. Search her posts & look at 1) Master Bath Tub & 2) Koiflowers. The 2nd one actually has some really good close-up views.
I do not want the feel of being boxed-in & thought her re-use of shower doors for the wall panels was a great idea. Plexiglass sheets would be great but none of my local bldg supply stores carry any thick enough & the shipping costs for ordering is almost more than the product itself! Had resigned myself to buying 2 new shower doors when I spotted an ad on craigslist for hurricane shutters! If they are still available, I've got my 2 walls. Hubby is a journeyman pipefitter/welder by trade so I will end up with one-of-a-kind framework for the shutters and overhead mounting which will be about a foot below the ceiling. A shower curtain on a curved rod takes care of the opening between the 2 glass walls.
For the 2 existing walls in lieu of tile I am going to use waterproof wall panels, either DPI tileboard or FRP wallboard. Both are reasonably priced & available locally.
The carpet.....what egghead came up with the idea of putting carpet in mobile home master baths! Regardless, its gotta go. I want wood floors so my choice is the vinyl laminate planks. Hubby says, no way, bad idea for a wet area. Guess we could duke it out in the front yard to see who wins but I'd probably be better off to choose my battles & let him have this one.
Seems Mark440 & I both use our garden tubs in the winter! I live in (extreme) SE Georgia & Mother Nature's freak cold weather joke turned my tub into a greenhouse. No worries with water stains but a few uninvited critters did manage to hitch a ride indoors.
BTW your existing garden tub already has a "sit & wash your feet" spot of sorts. Not a bench but its still a place to park. Might want to reconsider conversion vs tear out & replace.
Hope this helps!