for that kind of money you will probably have to pick up something used...
maybe a canon d30 or d40 (if you can find it cheap on ebay)... the rebel is cheap as well...
I am not a Nikon user but if you have lenses that fit their digital cameras you should think about getting a Nikon. So you know if your lenses fit nikon digital bodies?
Sony makes cameras but Nikon been in cameras forever and they use SD and SDHC storage witch is not true fore Sony. SDHC us cheep and and easy to find.
i would not go sony for one reason memory stick duo i hate it hate it hate it
sd is much better
SONY DSLR CAMERAS are not has good as CANON and NIKON anyway NIKON D40X could be one to look at and NIKOR lenses and CANNON lenses are just about the best.
It is a matter of do you want to continue shooting nikon or switch to canon?
If you want to continue with nikon I would go with the D40, its a solid body with good controls. Heres the bad news, If memory serves me correct when Nikon transition to digital SLRs they had to switch to Nikkor DX series lenses for operability on the new camera bodys, so I do not believe your older nikkor lens from your fm10 would work on a digital unit.
Butttt, since im a canon guy, do this..
If I was in your shoes I would just save $500, go on ebay, get yourself a canon digital rebel XT, 8MP. And a canon EF 28-135mm/IS/USM lens. Thats a great camera body/lens combination to hone your skills on.
lol, Sony are dominating the sensor market. I used to be a Nikon D3/4 shooter for years, believe me.,.. sony are the future, canon and Nikon havent done anything new or good in years.