Jombati, who was released by Cheltenham Town earlier this week, has penned a two-year deal, while Wood has agreed a two-year extension with the side.
Manager Gareth Ainsworth told the club's website: "I've seen Sido play many times and he's always caught my eye. He's tall, very quick, athletic and good on the ball. He's also an outstanding professional and I'm sure he'll be a really good addition to the squad.
"Sam is a really important part of my plans and to keep him here is a massive plus for me, his teammates and the supporters.
"He's coming into the prime of his career and it's great he's agreed to be a part of our plans for the next two seasons."
Wycombe narrowly avoided relegation from League Two in the 2013-14 season, finishing 22nd in the table.