I have to say, gimp is the best. You can do just about anything and if it seems impossible, you can develope a plugin to do it, many times with the help of other gimp enthusiasts.
Corel had a version of wordperfect and corel-draw adn phot-paint all for linux. They even developed their own linux distro at one point. It looks like they have sold just about everything that they had that involved linux, and they have seemed to have discontinued Corel-Draw and the others. You might be able to buy the software, and license from someone.
Another great option is Star Office, from Sun Microsystems (
www.sun.com)/ It is an office suite very similar to microsoft office applications, but it runs on many paltforms, the files are compatible with microsoft and it is better. Oh, the best part, it is FREE! It comes with a word processor, spreadsheet, databases, and many other features, including a great drawing program. This is a drawing program is not like a photoshop program that is mainly for touching up photos. It is one where you can draw shapes and lines and free-hand with the mouse. It sounds like this is what you are looking for. Either way, the Star Office Suite is a must have for all linux and unix users. If windows users were smart they would take it as a free download as opposed to buying or stealing the microsoft crap.