Alright guys, I am currently looking around at shopping for a new camera body. I am curious as to what you guys think. I own an a100 with the kit lens (yes I know, throw it out), a Minolta 50mm f/1.7, the Sony 75-300 f/4.5-5.6, and I am currently waiting on a Tamron AF 28-200 f/3.8-5.6 IF XR to get here. Oh yeah, I also have the Sony FVL-F58AM flash with a Gary Fong light diffuser. My question is, should I buy a new camera body? And, if so, which would be suggested?
Quite frankly, the noise produced on a shot from the a100 at ISO 800 is rather disappointing. I dont want to buy something better but still have disappointing shots at "high" ISO settings. I know that this kind of comes with the territory, but is it any better on the a380, or a550?

Also, is I am going to spend the money on the new body should I SAVE and get the full frame a850 or a900? Speaking of which, what is the major difference between the a850 and a900?

Any help or suggestions would be appreciated....