grouping of VENDORS

hi all ,

i have two req...

Fist one is

i have 5 vendor of the same group and while i run a vendor balance report, i want to have the total group wise balance.

Second one is....

I have a FERT material,which have a different packing size like 200 lts,100ltr,50ltr,25ltr.

i want the cummulative value of the materials..

How can i do that in the R/3 system. we r in 5.0.

regards

Praveen