why are u only considering the s5000? ur s7000 has a hotshoe but
i dun think it has a 10x optical zoom reach.
anyway a dslr can reach ur 12x (420mm) most dSLRs have at least a
1.5x crop factor (s2pro, d100) and 1.6x (d30, d60, 10d) which means
a 70-300mm lens reaches at least 450mm. with a TC of 1.4x or 2x, it
goes even further. of course all this equipment isn't cheap, but
the point to illustrate is that going LONG is easy, going wide
isn't. i'd be concerned with ur widest setting, with or without
wide convertors. as with any convertor, u lose quality, even if
quality is negligible, u lose LIGHT. then u add filters etc etc,
even more light gone. losing a stop of light in already poor
conditions is more than a pain in the ass.. it's more like a poke
up ten feet! 
okok anyway! i know u've been hunting around for a new cam with
manual functions. if u really wanna stick to digicam (meaning not
go to dSLR) i would advice u to get one with an EVF. start using
the viewfinder to frame ur shots to really improve ur composition
and ur handholding techniques. with an EVF u can see all ur
settings, shutter speed, aperture, iso value, wb setting, flash
on/off/fill etc etc. so u no need to look at ur lcd and look back
into an OVF.
another thing that u might wanna think about is ur storage medium
XD is very expensive. i'm sure there are advantages of it, but for
me i will still stick to CF, cheap and fast enuff. don't forget the
s5000 will be shooting 6mp (if u use the super CCD at highest
settin) and with more noise at that setting u'll be having bigger
files. i'm using a 5mp cam and i get problems with a 512 and 128.
of course i shoot heaps on one day, but i have a laptop to d/l.
even then it's not all the convenient.
next thing to check is battery. u either get heaps of spare batts,
or use AAs, or get a batt pack, if the cam supports it. check out
ur power options on the cam b4 u buy, and the costs of these
options.
if u are worred about purple fringing and noise, i really need to
ask u how u are gonna present ur photos. most of us present them on
an online album at a MAX of 800pix on either side. even if u print
on 4r, the effects of noise and purple fringing aren't all that
apparent in any of the "reputable" brands of cameras. if u
CONSTANTLY need to produce 8R or super 8R shots then of course u
better be worried. i dunno about u, but i've never printed any
shots unless i needed to for OTHER pple.. like my brother's
wedding, and the wedding that i just did. other then that i haven't
been bothered to get large prints on large format inkjet for those
shots that i totally love and want to frame up. not cheap, those
prints. otherwise i won't bother printing 4R and storing them in my
drawer for the next year.
ok that's all i can think for now. i won't be recommending any
brands or models, since i haven't had much experience with other
cams except mine. if u wanna buy a 5700, then by all means ask me
all the questions about that cam that u want. 
