i'm shooting with my nikon and a canon (a friend gave me a great deal on it). i have a couple of manual focus lenses for the nikon that give me great, sharp pics...unfortunately, my eyesight is not what it used to be so using them is a crapshoot so far as focus goes. i find that i rely more and more on the autofocus lenses.
the canon came w/ an 18-55 f3.5-5.6 that's very serviceable. i wouldn't mind having a 50mm 1.4 or 1.8 for low light, indoor shooting. it's fast enough to accomodate the low light and will lessen any hand shake from handheld shots. i'd also like to have one for the nikon as well.
i'm not very happy with the autofocus lenses i got with the nikon. the focus is just a little too soft. i'd like to have a 70-200 zoom. that covers a lot of range...couple that with a 1.4x teleconverter and it's close to a 90-280 zoom. i like the teleconverter i have for the nikon and would invest in another for the canon. it's small and gives me an "extra" lens. problem with that is that you lose an f stop or two when you use it. longer lenses with 1.4 or 1.8 f stop are hideously expensive, though.
that's as far as i've gotten on considering lenses right now. i'll keep an eye on craigslist and the pawn shops, though...you can sometimes get a great deal.
i'm finding the wider angle lenses are working nicely for interior shots with marginal lighting. i'm having to learn to shoot action sequences. fortunately, it seems the director will run the actors through the scene a time or two before they actually shoot. i've been reading a little about sound blimps...they deaden the shutter noise in the camera, which allows for shooting while filming is going on...without the sound being picked up by the sound boom. since those are insanely high, i may look into making a couple for my cameras. i swear my project list is getting unreasonably long.
the film i'm starting on today seems to be more character/plot driven than action. i'm hoping that will make it easier to shoot. we'll see about that, though.
hope this answered at least part of your question...i'm just now on my first cuppa coffee and don't make sense to myself either.