There is a site with a big index of old flashes and the voltages they put ie - ie, if they're safe for DSLR use. I use an old one sometimes as it's my only one with a swivel head.

But I'm more likely to handhold my modern flash. One thing with an old flash is that you will want to shoot in Manual mode. The back of the flash unit will usually tell you what ISO/shutter speed/aperture to use.
As for the lenses... the 50mm F1.7 is probably decent (fast 50s are usually pretty decent), but the zooms are probably mediocre at best. The good news is that they all say "auto" which
probably means that they have an "A" setting on the aperture ring, which makes them very easy to use with your DSLR - you'll need to manually focus but otherwise you'll use them like a modern lens.
If you don't have a fast 50mm yet and the bundle is cheap, then go for it - but keep your expectations in check.

I will even admit that I've got a Sears 80-300mm in my collection somewhere - my initial test shots were awful but since then I've gotten a few that were surprisingly good. It is fairly large and heavy though.
edit: I just saw the price, $80 - I personally would not buy them for that. But then, I already have three K1000s.

The zooms are pretty close to valueless - check eBay or Pentaxforums and you'll see that no-name zooms are dirt, dirt cheap, because nobody really wants them. You can pick up a used but relatively newish Pentax 50-200mm for $100 or so pretty often that will have better picture quality than those zooms plus has autofocus (and is much smaller and lighter), and there are a zillion high quality 50mm manual-focus primes out there for not much money. Now, if you have interest in shooting film, too, then maybe... but if you aren't interested in that, I would skip the whole package. I love K1000s but there's a ton out there (IIRC it's the best-selling SLR ever) and you can find Pentax film cameras on the cheap all the time on Craigslist, eBay, and Pentaxforums.