There's an outstanding bug (3 years old at the time of writing) asking for a native PECL provider and a similar, older one for Pear packages. It doesn't look like either of those will be included in Puppet any time soon.
There are PECL and Pear providers here which you could include in your Puppet setup. There's also another PECL provider here. I haven't tested them myself and I can't vouch for how easy they are to use or how well they work.
The best suggestion I have seen involves re-packaging each PECL extension you ant to use as
.rpm packages and either running your own internal repository or pushing the package files out through puppet and installing them via
rpm. There's a HOWTO for Debian-based distros here.
For your situation, you would install the PECL extension into a staging directory on a dev box, supplying the required command-line options manually, and then package up what gets created into a package for your OS package management system.
The upside is having a single package management system rather than all of apt, pecl, pear, gem, etc. The downside is that since you would be repackaging these extensions yourself, you will still have to monitor the upstream providers (pecl in your case) and update your packages whenever a security patch comes through.