For the mystical place between the magic user and the cleric, Castelli & Chimere offers the Occult Healer class, for members of this little-known order of physicians. The class has a smattering of martial arts, uses a spellbook, has healing skills, and also has a very distinct vibe to it that works quite well, I think.
Also, a shout-out to one of the game's longtime supporters and an awesome artist, Bliss Infinite has what might possibly be my favorite banner illustration of all time. His post for Swords & Wizardry Appreciation Day is a collection of links to a lot of different resources. You scroll down, and scroll down, and keep scrolling ... awesome stuff - races, character sheets, books of spells ... Highly recommended!
Need an adventure with vikings and degenerate cavemen? That's almost a rhetorical question: everyone needs an adventure with vikings and degenerate cavemen! Take a look at the Caverns of the Skraelings by Dave Baymiller.
And to keep track of these characters, here's an absolutely incredibly super-cool character sheet from Fear no Darkness. I kid you not, take a look at this.