Thanks for the detailed analysis.The key word i guess is WANT.
Since you Want a DSLR badly. And i assume that 1k is what you're willing to spend on.
i believe fellow bros have given u the options already.
Now u need to ask urself what you NEED in that new camera body.
Nikon, Canon are the famous brands. But for 1k. They do not really give u alot of bang for the bucks and they have the most accessories... which at this point of time may not be a good thing for you.
My advise to you is to decide what you NEED for this DSLR and get something which will last u for at least 2 years. Shutter counts are what you need to look for if you are getting a 2nd hand.
The rest of the Needs are list here.
IS : Image stabiliser or anti shake (If you have been using a P&S with this function prob might want to have this.)
Live View : Most entry DSLR don't come with this function. (Unlike P&S you have only the viewfinder on most DSLR, no picture on the lcd screen behind)
Dust removal : Most come with this technology recently. But personally i think this is a must have...
Auto-focus: I know the D40/x does not have AF within its own body. So you may want to take that into consideration.
External Flash : Believe me... you WILL get an ext flash. so do include this into your budget.
Tripod: This is a may or may not. But if you're thinking of long exposure or night shots... or even nice landscape shots. But this can wait... and there are some cheaper alternatives here in CS ads
Crop factor: This is a little tricky, its more on sensor size, nikon, canon are 1.5 crop, Pentax is 1.6 if i'm not wrong and olympus is 2x. Meaning if you see the lense having 50mm- 100mm it actually means 75mm-150mm for 1.5 crop and for 2x its 100mm-200mm. There is a multiplication factor to these. so its a choice for either WIDE angle or Telezoom.
Lens: most important NEED. Get a good one so it can do most of the job for you. a range from 14-18 to 50-70, depending on the crop factor is good for most shots.
do some search of the items which you are thinking about in the CS forums you will find alot of "gold mines" here which have been discussed and shared by alot of bros here.
Hope this helps you