"...a pleasure working with you..."
It was a pleasure to work with you.
"...can't thank (Kathy) enough..."
"I can't thank you enough for your help."
"...definitely recommend you..."
If I know anyone interested in buying or selling I will definitely recommend you.
"...almost gave up...until we found you..."
We gave up on getting our home SOLD, until we met you. You sold our home when others couldn't.