A medium kritter keeper is good for most adult terrestrials. I find a 10 gal to be over kill for 5-6" spiders. I use these for my terrestrials http://i.walmartimages.com/i/p/00/07...10_500X500.jpg
Any thing in the Brachypelma genus will be fine, Aphonopelma is a cheaper option, Grammostola, Avicularia, and Eupalaestrus are all good genera for beginners
Read the review section way at the bottom for peoples history. Most of my collection has come from other hobbyists.
I feed my slings once a week. A sauce cup is great for slings for a few months http://i01.i.aliimg.com/photo/v0/272..._Sauce_Cup.jpg
I generally see B smithi at about $30 but you can get them for less especially from hobbyists.