As far as drum machines go, I use a Boss Jam Station. Model is "
JS-5" My teacher, Anthony Wellington, turned me on to it. It's indispensable. Not only does it have nearly every drum rhythm you can name, you can set up all kinda of chord based or tonality based grooves. Makes working scales and arpeggios fun. Boss doesn't make it anymore, but you can get them on e-bay. It has no moving parts, so they last forever.
I also like the Tascam BT-2 bass trainer for playing along with CD's, but it's junk. I've gone through 2 of them in less than 2 years. The CD trainer I really want is called a Superscope, but it costs like $900. Pretty steep entry price...