Not sure what the inklet tool is since it's for mac, but it seems similar? I don't think it matters what kind of tablet it is. The more expensive ones are usually used by pros from what I've seen and if you want to look at what you're drawing on the tablet. I have Bamboo and that's sufficent for me. It'll take a while to draw and look at the computer screen at the same time, but you'll get used to it. You'll also have to buy your own pen nibs, so depending on how often you draw, it might be pricey in total. I'm one for being on a budget,but it's up to you.
Not saying that, why not stick to SAI and GIMP? They're free and I don't think there's much difference between any programs. I've also used IllustStudio and Smoothdraw too, and they're good. Smoothdraw makes the lines smoother than any program I've seen so far actually. I would actually pick a program with the file size in mind. You don't want something taking up so much space that it affects how the computer runs.
Hope I made sense!