I found the product specifications here. Based on that, you should be able to upgrade the ram to 16 GB. It also looks like there are some faster processor options as well. Another source to look at is the Maintenance and Service Guide which will show you what options may have been shipped by HP in that product, which is a good indicator of what will likely work. I'm not sure about the bt848 card, these SFF PCs often don't have a lot of room for expansion cards, so you may need to do some research to find one that will fit in the space available.