Beginning programming for Atmel uProcessors
Based on your intent to use AVR Studio, I will assume you are wanting to develop in a Windows environment. Most of my recommendations below are portable to unix-y systems as well.

You should do the following:


Download / Install WinAVR
Download Eclipse IDE for C/C++ Developers
Follow instructions to install the AVR-Eclipse plugin.
Make a new project targetting your desired chip and get a blinking light working. Proceed to more advanced things from there.
You can use AVR Studio to target your chip with a hex file, or you can use avrdude to do it from the command line (the programmeres you suggested should both be viable in either case)


The concept of using a bootloader with an ATtiny is not a great idea, imho. You'll need additional support circuitry to do that (a USB to Serial converter and associated reset circuitry at least), and there is certainly some software complexity involved, as the ATtiny's don't generally have bootloader support built-in (no BOOTRST fuse for example). And you are typically already very space limited as it is.