If you havent bought a boat yet then you would be cracked in the scone to buy one which you need to make a major modification. There are zillions of boats that fit your neds and budget in the USA so it would only be laziness neglecting to find the one that better suits.
On to the tiller vs wheel for cruising. I much prefer a wheel than a tiller and would not have a tiller on a cruising boat. Its not really a technical thing, its a thing thing... It gives the feel of a boat of substance where a tiller gives the feel of smallness. Sure that may just be a kinesthetic thing, but its why we make many decisions... Its got to feel right. (Its one of the reasons why cars that resemble rice grains on wheels dont sell as well as "proper"cars..... till the fuel price is so high we are forced).
If your boat is to be your home you need to love it.
The internet image search shows most Tartan 34c's to have wheeels, so you cant be looking hard enough. But i do note, as others have, that theres no cockpit room with the wheel. Even with the tiller there is stuff all cockpit room!
See the attached photo. To get throm aft the wheel to the rest of the cockpit you can not step around the wheel you gotta step up onto the seat then back down. The Fun Police would shoot that after a while. If you have young kids it could become a safety thing at sea.
Maybe you are looking at the totally wrong sort of boat? Is a narrow boat going to be the thing with a couple? Where do you go to have a meter or two of space?
I know that Tartan is meant to be a real yachtnand none others exist, but have you let the fairer half of your relationship have a look at more modern design boats? 50 year old design is not 50 years young, its 50 years old. It would be the only appliance, mechanical, electrical, moving, fixed etc you have ever owned to be so old.
It sails on its ear, into the wind it sails on a 30 degree+ heal in light weather which might be fine for guys, but girls? Modern boats do it at 15 degrees unless v heavy weather.
The good feeling you want from your new boat is many, many things. The looking and the buying is both fun and frustrating. But one thing I know: Your perfect boat is out there. You just need to ensure you find the real one.