As it happens, I like "try us out", as it subliminally suggests that they aren't committing themselves. Provided you doa good job, they'll be yours with just the usual drop offs from people who did want a one-off. They'll call whatever you say.
As for the rest, I don't think any of the wording wouldn't work. Plus, I always do what my wife tells me to do, so I wouldn't have a say.
Vin