Alex Corbisiero, Jamie Roberts and Mike Phillips are all fully fit for the third Test, while Sean O'Brien, Toby Faletau and Richard Hibbard also come into the starting side.
Gatland has left out quadruple Lions tourist Brian O'Driscoll from his matchday 23 after deciding to partner Roberts with Wales team-mate Jonathan Davies in what he has since described as one of a number of tight decisions ahead of the must-win encounter at the ANZ Stadium.
"It was quite a lively meeting we had with the coaches last night in terms of going through and making the final selection. It was tough but we've come up with what we think is a side that's good enough to do the job on Saturday," said Gatland, who says the large number of changes will be a help rather than a hindrance in the quest for a first series success in 16 years.
"There are always close calls. A few players came back from injury and for a quite a few of the positions in the side between the first and second Tests there were toss up decisions there as well.
"We've been together for a few weeks now. There were a few injuries last week, we were forced to make a few changes through injury. There's been a lot of competition within the squad, past selections have been tough with tight calls. The changes we have made, we think are going to strengthen the team for this Saturday.
"Obviously, Brian (O'Driscoll) was disappointed, as anyone is, but he appreciated the fact that he was spoken to before the announcement. It's the first time that any coach has had that decision with him in 15 years of rugby. It's not easy for that to be the first time, but he's still going to be very important for us for the next 72 hours in terms of his experience and leadership. He's been involved in the first two Tests, but Jamie's back fit and Jamie's been given the nod in terms of that partnership with Jon Davies in the midfield."
Jones will lead the Lions for the first time this weekend, with Gatland convinced that the Wales and Ospreys lock has what it takes to guide his troops to a famous victory.
The 27-year-old has led his region with distinction for the past three seasons and Gatland is backing him to combine the captaincy with another powerful display up front in the final fixture of the 10-match adventure.
"Alun Wyn leads from the front. He's been outstanding in the lead up games and was one of the first names on the sheet when we picked the team for the first two Tests. He'll go and lead by example," added Gatland.
"There's a little bit of pressure taken off him with the fact that Geoff Parling will be calling the lineout, you've got leaders in other positions as well, he'll just be an important part of that engine room that needs to fire for us on Saturday.
"There were a number of candidates but it wasn't about picking a captain first, it was about picking what we felt was the best team first. We did that, and then we went through the next question was who we felt could do the best job in terms of captaining. Alun Wyn gets his opportunity on Saturday."