I'm not an expert on this, but here's my experience as a very particular, very frugal woman. I don't believe in spending gobs of money unnecessarily. If you're resourceful you can save yourself hundreds of dollars, as I did.
I also do not want to be too stretched out on a bike, and I can't even contemplate spending money on a Terry. So here's my $635 dollar solution:
I got a really tiny frame. I'm 5'5", something like a 29" inseam, and I went with a 47 cm frame, well below what I used to ride on. I had huge doubts about that, but my LBS proved to me that they could get the exact position I wanted, down to a fraction of an inch, by adjusting the position of the seat, stem, and handlebars. The key was finding ***EXACTLY THE RGIHT ADJUSTABLE STEM*** to get the handlebars 1-2" above the seat and get me in a moderately upright position (or moderately stretched out, if you prefer to express it that way. They mean the same.).
I was only able to get the position I wanted by going with the smaller frame. Now, there are some problems with this for touring.
First, we're talking about a road bike, in my case the Trek 1000 WSD. So you're not going to have two sets of eyelets front and back. But you can put fenders and a rack in the same eyelet by using a longer bolt.
Second, my frame is too small to accommodate all the water bottles I want. Again, there are ways around this, and since you're taller than me you might be able to find a frame with bosses for 2 water bottles (although I feel that 3 are needed for summer touring).
Third, be very careful about heel clearance for your panniers. This is reduced on a road bike with a small frame. I was amazed to find that I have just enough clearance on my bike, so it's not hopeless.
Fourth, make sure that you will have enough space to mount fenders. This is a factor of your tire size and brake design.
Fifth, you willl want to change the gears of any road bike you buy. Changing gears means getting a longer rear derailleur. If you change the chain rings (which you will want to do) you need to carefully check your crank length.
You will also need to change the tires. I recommend 700 x 28 tires.
Your situation boils down to finding a bike that
1) You can afford
2) Will give you the more upright position you want
3) Can be converted to a touring bike
You will clearly have many more choices of frames if you buy a road bike rather than a touring bike, and you will be able to save quite a bit of money.
There is no reason you can't convert a comfortable hybrid to a touring bike; in fact that will most likely be easier than converting a road bike as you will have more clearance for fenders, maybe more eyelets, etc. That's assuming that a hybrid handlebar will work for you. Putting a road bar on a hybrid will entail work on the brakes and cables.
I concluded that once I got my road bike set up to fit me perfectly---which took the LBS two weeks to do because they changed practically everything on it---I should stick with that for touring and just deal with the touring conversion problems creatively. I don't want to go through the same hassle and expense all over again to get an already expensive touring bike to be comfortable (like getting rid of the bar-end shifters on the Trek 520). I don't even like the gearing on the 520 as I live in an area of steep hills.
My 2006 Trek 1000 cost $635 including all upgrades: full mountain gears front and back, deore derailleur, wider handlebar, adjustable stem, wider tires, and extra brake levers mounted on the handlebar, and they installed my existing rear rack and computer. I defy anyone to find a better bike at that price! I don't believe there is a touring bike under $1000 with those features.
The main thing I want to point out is that frame size is not the most important consideration for you. The most important consideration is BODY POSITION. ***You can achieve what you consider the ideal position in more than one way, by varying the frame, seat, stem, and handlebars and how they all work together.***
So I suggest that you test a smaller frame as follows. First determine your ideal body position (perhaps on your existing bike) and figure out the exact distance that you want between the top of the seat tube and the handlebars, and your seat height to achieve that position. (Be careful about your knee position when you set this up.) Take a tape measure with you to the store and test various set ups on a couple of different frame sizes with several different stems until you are able to get the exact measurements you want. Choose an LBS that is willing to be really patient with you in this process and is not going to charge you a million bucks to make the swops.
My LBS didn't charge me a single penny for changing virtually everything on the bike, including several upgraded parts. I love those guys. I realize that not everyone will be this lucky with their LBS.