is it woprth getting as much RAM as possible.....16GB. Friends have told me that only prgrams thats are specialised will actually use the 16 GB.
You dont say what programs your going to use or what type of programs.
Even in this day and age of multiple 64bit operating systems alot of applications are still only written for 32bit platforms, this means even though you may have 8,10,16 or more gb of ram the maximum addressible memory by that application is 4gb (of which most wont address above 2gb for legacy reasons).
The more RAM the better is generally the performance but typically (and agreed there are exceptions) for most home use anything above 6gb you will be spending money on diminishing returns.
If you have multiple applications running then you will get more efficient use of the memory, but with the windows architecture of memory allocation you will still find a swap file used even tho physical memory is available, so dont blow good money in the hope that its going to give you great returns.
Dual+ graphics card installations have been around for years and have never really caught on because there really is not much software that will take true advantage of the potential they offer. Its sort of a catch 22 situation in that most graphics intensive applications e.g. games are written to a common denominator of the hardware required - as the vast majority of platforms used at home are single cards (and not top of the range) most games will be optomised for that. Things are gradually changing in this area and you can spend huge amounts on the graphic subsystem which will only be wasted if your not using it.
Whats it you want to do ?