For affordable fast conversion you should try something like this;
http://www.elgato.com/elgato/na/mainmenu/products/Turbo264HD/product1.en.ht...
[Travis Roesler] "h.264
high quality
key frame rate 24
600x318 for dimensions"
For quality, set Multipass and the keyframes AUTO.
Restrict the date rate. For that size i would start to try something like 500Kbps.
rafael
http://www.nagavideo.com