[xelasnave]

First the dew shield...go to Office Works and look at the stuff they have..you may need to stick two sheets of their thick black cardboard together to make it all the way around the tube ( not too thick as you need to bend it without a fight)..I have just bought a pile of excellent black cardboard from Office Works and plan making a baffled dew tube for the new eight inch rig...( A lot of work but just look at the Hubble Space telescope and what they do beyond the secondary mirror on the inside of the tube then think as to why they would do that..you can bet there was a committee behind that..it did not get there because it looks neat)...
Make it fit well and just use blue tack to hold it in place...you can add mouse mat material which allows easy removal as well...blue tack is very handy while you are working out cabling...do not try to go permanent with cables first up ..(and when your camera plays up it most likely will want a very expensive USB cable..almost a necessity..well it is really..and with blue tack you move things around adjusting after having seen what happens during a session...it also helps a little if cables snag by letting go before real damage occurs..even with Asiair plus be there until you have been present a few sessions.

With the dew tube being cardboard paint it to protect it from dew... baffled or not and on the inside liberally apply black paint and while that is wet sprinkle saw dust ..allow that coat to dry completely and apply another coat of flat black paint...the idea of the saw dust is to reduce reflection..Celestron have a dew heater ring which is a good idea as you can use it to mount your cable routing thingy...look into that or ask if you need...the cable must follow a particular path across the corrector plate.

As to camera ..forget the money and work out what is best..dont make excuses just accept that is what you must do....compromise just brings all your gear to the level of the lowest unit...go to Bintel Web site and play around with their calculator that matches cameras to scopes and tells you if the combination is over or under sampled... it also shows the framing on familar objects which I think will be helpful for you.

In any event get the best camera you can and the one that is appropriate to your scope....using a price range as your criteria is asking for disappointment...you may have to wait more months but just remember a "less than" camera brings everything down...and finally you go buy the one you should have bought day one.
If the camera you should get is out of the question perhaps get a cheaper uncooled mono camera that eventually you can use as a guide camera... AND when you can buy the best camera for your rig.

Alex