I think Mark is a little confused - he's thinking of the D40, not the 40D. (Darn it, Canikon, keep your names a little more different!) The 40D is more comparable to the K10D/K20D.
Still, I guess I'd also wonder why a 40D body - unless you're going to get an M42 adapter and use your current lenses, you're looking at getting a pile of new lenses, and
IMHO if you're buying Canon lenses, you need to buy the high-end ones to get decent quality, so you'd be looking at a decent pile of money. Since you obviously have a taste for manual-focus primes, it wouldn't make sense.
Now, I have heard of shooters of other systems picking up an older 5D purely to give you a FF body and the ability to mount many difference lenses on it (although I think some M42 lenses have issues with hitting the mirror.)
If you're itching for a new body, I would save a little longer or dig a little deeper and grab a K-7 - they are really quite incredible, especially if you're moving from a K100D/K200D.
Oh BTW, if you want, I have a K1000 here that I could send you as a thank-you for the Spotmatic, if you'd like such a thing.
