Setting up Varnish and W3TC is relatively easy and can be done in 20-30 minutes, the only issue you may run into is with tokens that are generated by database management plugins or software.
These tokens are not supposed to be cached and unless you modify the VCL to pass, you won't be able to log-in and use them. You'll still be able to log-in to WordPress, but if you use the Adminer plugin (either the WP plugin or stand-alone), SQLBuddy, phpMyAdmin, or other software, you won't unless you add that pass to the VCL. I've still not managed to find the right line to add, though if you need a starting point, we use the configuration below on quite a few deployments.
It works well and it's really copy & paste.