Two things: mind that the dependency for PyQt is for PyQt 3.x; though not stated more specifically on mnemosyne's website, you probably can't -- and definitely shouldn't -- use PyQt 4.x. Your PyQt major version is probably the same as that of any KDE applications you have installed.
Second, sbbuilder does leave some fiddling to do before one gets to the coda in this case. The script generated by sbbuilder is intended to be altered before use, indeed gives some commented hints on how one might do so. Generating a script with sbbuilder is worth the time, as it will give very good info whether you alter and use that script, or write one yourself. Among others, include the option --type="python".
Oh, yeah: sbbuilder --manual. If you'd like for that to come up as "man sbbuilder", as root do sbbuilder --manual | gzip > /usr/share/man/cat1/sbbuilder.1.gz .
I had a go at this with sbbuilder. Though it looks to be easier than other things I've been working on, I gave up when warned a Python script was missing. My plate is full, and though I'd like to have mnemosyne I haven't seen it so don't miss it.
It's always nice when someone who's familiar with an application does the initial packaging and testing. Hope you will see this through, but don't sweat it.
I did find a package for Zenwalk, but I suspect it's for 64-bit.