The BEST leaf blower is a 4 cycle gas model made by Makita. As a gardener by trade, I've used many brands including Echo and Red Max and the Makita is the best by far. It's very easy to crank, I've never had to pull it more than twice and it pulls quite easily.
As to blowing your mulch away...it's a matter of technique. If you hold the nozzle at a 45 degree (or more) angle yes it will blow your mulch. But if you hold it a a very slight angle, almost parallel to the ground and grazing the top of the leaves, it will just blow the lighter weight leaves and leave your mulch intact.
I've had two gas models (can't remember the names of course) but finally had to get a plug in one..just couldn't start the gas ones anymore. I went for one with the most power and have been thrilled with it. Only problem is you are tethered by the cord. Since I only do my patios it hasn't been a major problem.