endeavour, hunter, irwin???
I too applaud your desire and say go for it. I also think you have gotten some good advice here.
Reading in between the lines, I believe I see that ''livability'' is going to be the issue...along with the desire for two private staterooms and shallow draft. That is going to be a tough nut to crack for 50k...but I think it can be done, given that you do not wish to go for a bluewater cruiser.
In general terms, I think you will find newer models more ''livable'' and in need of less upgrading than older ones. I stuck with boats 1980 and newer as a general guideline and this seems to have worked out for me. All boats need some upgrading. As the poster above observed, wiring, pumps, rigging...all add up. Fast.
I would say (again in general terms) search from 35ft-38ft, 1980 or newer. The sole exception perhaps being a slightly older Tartan 37 (that said, I am not sure this boat will have the cabin you want).
In my searching, I noticed a number of remarkable 38ft designs. Indeed, I got one. It seems that nearly every builder had a really nice 38ft design and the difference in cabin space between 38ft on up to 42 ft was relatively trivial.
As far as comfortable motion is concerned, we will no doubt have a debate here but I am in the heavier is better camp. This assumes a 1980''s vintage design and not a newer more modern, computer designed hull (obviously because of price limitations). Also, after single handing for quite some time in a 22,000 lbs displacement boat (a Wauquiez Hood 38, which I LOVE), I would also suggest using displacement (and LWL) as a guide to what you can handle and what might sail better. I am sure I can handle quite a bit more than a 22,000 lb boat....but I am much happier with 22 as the upper limit. Work is work, no matter what winches are involved. The heavier the boat, the more the work....anchoring, sailing, sail handling, etc. For motion comfort and simple, plain ability to blast through some chop, my lower limit would be perhaps 15,000 lbs (I know there will be quite a bit of debate on this...this is my personal opinion, nothing more)....remember, even a small wave weighs over 10,000 lbs.
As far as island cruisers, livaboard and Endeavours go...the build quality not withstanding...yet another debate...I have heard a few good things about the Endeavour 38 CC. Nice aft stateroom. Can be had for 50k.
A general all around good boat to through into the mix would be the Morgan 382, which can be had for around 50k. It does not have an aft stateroom (it has a qtr berth, but its a fine boat for the money and there are quite a few being used as livaboards.
You could also throw in a Beneteau Frist 38 into this ring.
Others to look for under 38 (although none of these have an aft stateroom):
Union 36 (with bottom job and teak decks done...probably higher than 50k)
Hunter 37 Cheribini
Sorry this is so long winded. As someone said, a difficult question to bound. Hopefully, this will spark some debate that will be helpful
All the best