Well wow factor.
this is a funny one depends on who you are for that! I run with the setup that everybody has spoken about the 10" SW Newt running aboard the EQ6 platform, the scope and mount costed a tad over 2100 (that was back when the $$ was good).
I guide with a DSE 114mm reflector (works a treat) and a DSI 1. As for the DMK and guiding ide steer away from them they arnt sensitive enough to pick faint guide stars (my friend leinad brought a DSI for this very reason).
One big thing your moutings will cost you a significant whack as knowing what i know now, get the biggest nastyiest set of rings to attach your 10" to a EQ6. secondly chuck the Vixen straw that attaches the rings and the mount head at a undesierable! they are useless and flex BADLY go for the Losmundy D style clamp 3" on the bottom 4" on the top. so you will be looking at approximately 500 +- to get the job done right!
I belive that a 10" is the perfect balance of portability/light bucketness/photography (deepsky/planetary).
as for cameras the 350D modded can be had for 400 - 600, but remember you will need a adaptor to take long exposures DSUSB and if you use the software EQMOD with a goto mount you can do away with the GPUSB (to talk to the mount for guiding) very easy and accurate.
All up if your looking to go to photography but want something to show people in the mean time this is my layout
Hardware
10" Dobsonian (this is so you can drag it out drop it and show people, then flick it up onto the mount for photography or large groups)
EQ6 Pro
114mm Guidescope
Home made rings/mounting solution (because i have access to machines)
Cameras
DSLR 350d minimum 20Da or modded 40D is preferable
Meade DSI 1 or 2 depending on price for guiding also doubles to check your drift alignment and to compleate your star alignments (handy for accurate alignments)
don't go with a 12" upon a EQ6 Pro, there will be limited nights you will be able to use it and the size difference from a 10 - 12 is ASTONISHING. that said the 12 has more light... thats my ideas on the budget end of the spectrum.