Jamieson, now training in Bath, made a big breakthrough by winning the 200 metre breaststroke at the British Championships in Sheffield in March and he will be making his GB team debut at the European Championships in Budapest in August.
Gilchrist moved to Paris with coach Fred Vergnoux after Edinburgh's Commonwealth Pool closed for refurbishment two years ago and the 2008 Olympian will be aiming to qualify for both the 100m and 20m breaststroke.
"It was great to make the European team, but it is the Commonwealths in Delhi in October that are the main goal this summer," said Jamieson. "You don't often get the chance to swim for Scotland and I would like to think that I have a chance of a medal.
"I moved to Bath last September and it is working out really well. Winning the British title was very satisfying and I finished second to Kris in the 100m which was also good for Scotland."
City of Glasgow's Robbie Renwick also aims to clinch his Commonwealth Games selection, but the event will be tinged by sadness. It is the first time that the 21-year-old has competed since his lifelong coach, Eileen Adams, lost her battle with cancer in March.
"It was a really sad time, and a huge shock," said Renwick.
Renwick has also qualified for the European Championships, but he is another who has pinpointed swimming for Scotland at the Commonwealths as this season's priority.
And he aims to make it a golden hat-trick in the 400m and 200m freestyle plus the 200m relay.
Hannah Miley, David Carry and teenager Lucy Ellis are the other Scots to have made the GB team for the European Championships and they will also be out to make sure of Commonwealth selection over the next six days.