You'll find that any method used, which mitigates the potential of damage to the dining room wall, will be expensive, may be the deciding factor and you'll be hard pressed to find a contractor who can legitimately say there will be no damage to the dining room side. This is the method that I have employed on several occasions, and keep in mind that these are full 2" x 4" stud walls. I used a 2x4 pocket door jamb amended to fit. The plaster and lath is carefully removed about 10" up from the floor. Metal brackets are attached to the studs at the bottom plate to add additional vibration damping, and the plaster and lathing removal is then completed. Metal brackets are added at the top plates. The nails are cut and the diagonal bracing is carefully removed. With the depth of cut set at 2-7/8" I use a beam saw to cut the studs for the top of the header height.(The wall may not be "load bering" but it's still weight loaded). Using a 4" grinder with a masonry blade, the plaster which has penetrated the lath is removed adjacent to the studs to allow clear passage of the table of a cordless skill saw to pass unobstructed. The DEWALT that I use is 1-1/8" table edge to blade. The studs affected are then ripped from the header cut to the bottom. The metal brackets are removed, individually, and using a sawzall blade with least kerf, the cut is completed. This DOES NOT affect the lath attachment on the opposing side. The nails attaching the bottom plate to the floor joists are removed and the bottom plate is attached in the 1-1/8" area that will remain. The bottom plate is cut and removed and depending upon the height of your existing door, filler is added or additional floor sheeting removed for the placement of the new jamb. If it's your decision to retain the aesthetics of a cased opening, the jamb will need to be amended to fit. The header and framing is set and the amended jamb is installed. With the jamb set, square and aligned, pre-drill the horizontal 1x slats in the jamb and attach to the dining room studs, further stabilizing them. A flat 2x4 is added to the side of the top plates on the kitchen side. A 2x4 is ripped to create a 5-1/2" wall thickness for the bottom plate and nailed in place. 2x6's are then ripped, installed and they are similarly attached to the jamb. The rock lath secured with screws and the gypsum plaster applied.

Thanks for the replies! Been busy at work and just getting an opportunity to check back in- the truth is that the doors function just fine, but are dated. It's truly just an aesthetic thing for me, which is why I hesitate to spend $3k+ on new. I'll attempt to post a pick, but imagine I'll fail on that!

I have a patio door with a single sidelight the same width as one of the patio doors. It looks like a 3 panel setup but only two of the doors open. I think they are 36" wide but would have to double check. So a bit wider that your existing opening. Looks similar to the door in the picture but i have two doors that open.

We do not close our closet doors..hardly ever. So, I am glad we chose double doors in our master since they take up less room when open and resting against each wall. For other closets a single made more sense. Double doors are more expensive than a single so keep that in mind. I like inswing for closets, since they are often left open....esp. by kids. For a pantry or linen closet outswing is my preference, since they will be closed. my master closet plan ..I did not use the shelves on each side of the door on the inside and the double doors stay open most of the time, resting against the wall.