You will only be able to put in what ever dell sold with laptop.I have had good luck with this nvidia 6800 in this 9300.When i put a new processor in(M780) it i also put Artic 5 on the cpu and gpu and chipset heat sinks.Ive noticed a big drop in temps on all.It does take a bit of work but its worth it.Ebay has some of these all the time.Just check and see what the options were when it was built.A go 7900 or 7950 might fit too,i dont know.

Thanks for your thoughts on my problem. You are right that I should replace my card with whatever Dell sold with this laptop and that is the Nvidea Go 6800 plus, also as you said one of the 7900 series cards is supposed to work, but they are expensive and according to other folks' experiences I've read, they run hot. I'm going to look into that Arctic 5 utility you mentioned, thats probably the software to enhance the fan speeds on the machine. But if you have had good luck running an NV go 6800 on an Inspiron 9300, then maybe I can get away with running other 9300 compatable cards on this M170. This probably depends on whether I can attach the Dell 170 dual pipe heat sink to a card for the 9300 since it looks (on E-Bay) like it has only one heat pipe.

Thanks again for your response, I'm still doing my research. 

The Go 7800GTX and 6800 were the only 2 cards offered for this system.