Balloon Framing, open web trusses.

Hi, I’m looking for some advice/ ideas.
So I own an old farm house built back in like 1890, the foundation has been completely redone prior to me buying it, the previous owner lifted the house and put a block foundation with a poured floor. It’s a two story home, length about 33 feet, width about 24 feet. My wife and I like open floor plans and this place needs a lot of work. So I am planning on replacing some old 2x8 floor trusses with open web trusses. The home is balloon framed currently and the original floor trusses run the length ways of the house with a load bearing wall supporting them in the middle.
I am planning on going to an open web truss the width of the house (roughly 24 feet) and being able to clear span it so we can get rid of the load bearing wall on the main floor and basement. Any ideas on the size of ledger I would need to support the trusses? I plan on a 18 inch tall truss at 19.2” OC.
Any other advice for me on this?
Also, anyone have a good way to cut the notch into the wall studs for the ledger?
Thanks!