I have a budding collection of reasonably inexpensive but good retro
compact film cameras and I'm considering purchasing a more serious
"photographer's" one to start using soon, as i safely know now that I
do like this hobby.

I'll use a budget of no more than $999.99.

I care most about *image quality*, as this will be the only reason I'd
want to step up from my film compacts. By image quality I mean both in
its original form (film/digital) or transferred to other media
(printed/scanned).

The choices i have are either...

- A quality film SLR (very easy to get within budget, heck, even $200
is enough for the pentax zx/mz-m).
- A digital SLR (canon or nikon; new or like new from ebay).
- an all-in-one 8mp digital, such as the canon or olympus.

How do these compare? (on the eventual *image quality* criterium only,
across media, regardless of eventual use of the image. I don't care
much about other features. Also, regardless of running costs, as I
have all I'd need to run a digital camera, from computer and
peripherals including memory chips, and film isn't expensive to run
after all when all things considered, it'd cost me ~$5 per 35mm film
total, purchased and developed, which isn't a lot considering it cost
me a few times that in day expenses when i went to a scenic spot
nearby to take pictures.)

Additionally, within that same budget, i'm also considering a Medium
format camera, such as a 645 rangefinder (on *image quality* criterium
only. Film isn't much more expensive than 35mm, and weight and size no
issue as none of above will fit in a belt-pouch anyway). How would it
compare to the above, especially to digital SLR? Even more, how would
it compare to state-of-the-art digital such as that $8000 canon, or
the 14mp new Kodak, because if it is favorably comparable it may mean
it'll be better for me than affordable digital for some many years to
come.