I currently have Suhosin/eAcc installed. Can I get Zend installed as well?

Define Zend. The core PHP engine? The "framework" that isn't a framework, just a bunch of libraries? The source code protection (Guard)?

The ability to run encrypted code

Sure, that is why suhosin was made because the regular hardened php doesnt allow included binaries, suhosin does.

Of course you can still install the zend framework/zend optimizer to be able to run encrypted files...

The Zend Optimizer is a free application that runs the files encoded by the Zend Encoder and Zend SafeGuard Suite, while enhancing the running speed of PHP applications. Many scripts require that you have Zend Optimizer installed so you are able to run them on your server while decrypting and running them on the fly while increasing runtime performance.

If you are using a cPanel server you can install it by either running script
/scripts/installzendopt or by enabling it while running /scripts/easyapache.

Yes you can still install Zend Optimizer to run the Zend Gaurd encoded files. The Zend Optimizer can only interpret the encrypted code. In order to actually encrypt it, you will have use the Zend Gaurd. This application will convert all of your plain text PHP code into a new binary format, known as Zend Intermediate Code. When encrypted, the new files will take the place of the regularly coded PHP files.

yes, but is their a trick to getting it to run with eAcc? i just get 503 when i include the files.