my Nvidia G force 85 will not support that resolution.
Do you mean Geforce 8500 like the example here
For larger screens and HDMI output you will need a new add on video card, please see my canned info below;
Please note that before purchasing an add on video card that the following must be considered;
Is the present PSU (power supply unit) powerful enough or will it also need upgrading.
What type of case do you have, full tower, mid tower or SFF (small form factor) this is important as you must make sure that there is enough room inside the case for the upgrade/s, upgrading a SFF type system can be difficult as they often use propriety components such as smaller and differing shape PSUs and they only have enough room inside the case for a low profile type add on card.
To help things along, Biostar P4M900-M4 Ver. 6.0/6.1 MB specs here