Walls and Ceilings - break down a bear loading wall

I would like to open two rooms and use it for new living room space, between two rooms are wall and one closet wall behind that wall (both walls are load bearing support walls), after I broke it down , I found out the beams of the first room is ending with double 2x4 support wall, and begin at the wall of the closet is another double 2x4 support for other beams in second room, both rooms' beams meet at end and begin but has own double 2x4 support wall. now I would like to cut at end and begin of those beams (2 rooms) to fit in 3 of 2x8 and each beam has own 2x8 bracket ( those beams in two room will sit on those brackets )and I will break the two old support walls. the room width is 12 feet 3/4 but I will build two new walls to support for 3 of 2x8 , that means I open new space between two rooms about 9 feet width. do you think that is ok, will new frame can handle and support the second floor. I have 4 bed rooms up stair and the new space is on first floor. the other two bed rooms up stair are above kitchen and dinning room side.

you'd bettet speak with a building inspector in your municipality to ensure adherance to local code. This isn't the usual DIY project and you must take care and get a permit. No matter how you describe this in this or any other forum I believe no one can get a clear picture of your situation.

I'd take Mudders advice on this one. Whats holding up the house now?? I've never seen a support beam/header made up of 2x8's. There always structural steel or 2 micro lams bolted together. Do you want this beam exposed or hidden?