Any carpenters, building a closet

So nothing to do with fishing , but I git to keep my wife happy so I can go
 
My wife wants to build a closet in the upstairs bedroom  It will be  28 inches deep from the  wall out.  Problem is that where the wall would go there is nothing above to  anchor it to, it's between 2 rafters. Nothing on the side walls either, between two studs I have thought of 2 ways around this short of tearing the ceiling/ wall down and adding the support .   Secure a piece of plywood to the ceiling from the back wall to where the wall will end.  It will catch 2 rafters with an 8 inch overhang from the last rafter.  Then attach my top plate to the plywood and secure to floor.   She can just paint the plywood white, it's the inside of a closet, or we could install drywall over the plywood.   Next is the same idea but use 1x4's   attached to the ceiling  catching the 2 rafters and put drywall on the 1x4's .   Would either work??????   The wall will support a sliding closet door.   Which would be stronger I am guessing the plywood right????
 
PS I am not a good carpenter so any help  is good

Hoping Charlie will reply as well.

Thanks Charlie. We will be using a hollow sliding door.   Thought about the molleys.   As lazy as I am and  even though I think they would work fine,  I wouldn't want a dog or a kid (maybe someday) crashing into the wall and it shifting.    I am fighting on this on doing it easy or doing it right.  The "right way"  would be to cut the drywall out and add the nailers on the ceiling and the walls.  For my limited carpentry skills I think the plywood with the dry wall over the top would be easier as I would not have cut the walls and ceiling for a nailer every 2 feet. I vlue your opinion and if you think the plywood will work I will probably go that way.
 
Thanks Clint   

Clint you mention the depth but not the overall dimensions.  What's above the closet space, attic?  Regardless of which way you proceed think resale?  Poorly done/constructed work will stick out like a sore thumb.      

clint ,  about 750 to about a grand  labor and materials.. frame trim sheet rock spackle to finish. and standard  pole hanger shelve rack sets vary in price.. custom wood is usually less expensive for those dimensions. It is typical glider track closet doors.Figure about three  to four 1/2 day labor sessions , I would suggest hire local with gas soaring prices, gl

John, my wife checked into it and your #'s are sounding bout right.  For that price we are going to do it ourselves.   I have the basic skills, but lack the experience.  I knew the "correct" answer before Charlie told me.   We are in somewhat of a remodel for that room as it was never finished from our build so there will  a  bunch of work.  Right now it is just 3/4 of the way finished sheetrock (just needs final skim and sand). New floor, molding  and a closet are on the way.   I would rather spend a few rainy days working on it and spend the $$$$ on gear or materials.
 
BTW I like Drennen and Froghair for my tippets. 

They are flouro.   Some like it some don't.  Here is my take on it and take it with a grain of salt  because it is not based on much more than  couple years for steelhead fishing and some reading.   
1: Flouro is inert and takes FOREVER to break down so be careful don't leave it lying around  (not that we should leave anything lying around).   That is enough for alot not to use it.
2:  Flouro sinks faster it is more dense also meaning it does not stretch and can be stiffer especially in the cold.
3:  Flouro is more abrasion resistant, and often out performs mono of the same test.   and I think holds knot strength better.
4: Different brands perform differently especially in cold weather.  Hot Tuna had really bad luck with Seaguar flouro in the cold but good luck with Froghair.
5:  It is less visable and in many cases thinner than mono of the same test.
Not based on testing and only a  limited amount of river time.  Some of the above may even be wrong,    take it FWIW.

Not really..
LOTS sell a product because thats the vendor discount bulk price..
While some things work well others are just geared toward 'here is what we stock"
 
I played in a bar once that said the only beer available was Corona..
Tried one and from then on out those 3 days it was Jack & Coke.. Congas never sounded better..