Hello Deadman Welcome to the forums, let me try and answer your questions:
Too set up your Avatar and Signature, look near the top of the forum pages and you will see a button that says Profile. If you click that, you will be brought to your own profile page. on the left side of the page you will see buttons that say Edit Avatar and edit signature. Click those buttons to set up your avatar and sig. Note this site also supports Gravatar (Gravatar.com ) and you can go there and set up an avatar for the email address you used to register your account here and that avatar will be used on your posts here.
As to item request, Jeff takes requests from time to time on the blog, but the two main volunteer artist dblade and Mad Jack take requests here on the forums on the following Topic thread: