What type of spindle is best is totally up to the spinner. I prefer a top whorl myself. One of my favorite spindles, believe it or not, is a spindle I made myself from junk CD's. It is perfectly balanced and long spinning.
There are a wide variety of spindle makers out there. From under $10.00 to over $100.00, it's all about design, wood it's made from and such. Spindles are very collectable and made from an unbelievable variety of raw materials. Even moose antlers and ancient prehistoric mammoth teeth! I have one spindle that I treasure that is inlaid with turquoise nuggets.
I would buy a spindle with a medium weight, and a medium size whorl. What wood its made from is up to you. One of my favorite spindles comes from Jeanne and Paul Hubbard a Simple Market Farms. Their spindles are made one by one by Paul and are truly works of art. Jeanne also has a wide variety of different fibers.
If you need any help, don't hesitate to write.