The 5.5 is preferable to the 6.5 pads simply as they can be worked in more areas than the larger pads. With that said there willbe some areas you need to be careful of as you'll be in edges and transitions.
As far as the cleaner and conditioner, get the cleaner on sale simply because it's cheaper and conditioner's are pretty optional, As someone else said just prime the pads with the product you are using, I spritz some Distilled water on the pad for it's first use and prime with the polish or lsp.
I'd also say the pads recommended by others is a good start, 2 orange, 2 white, 2 black should cover most situations to start. What size vehicle are you doing as 2 pads might not be enough for a large vehicle especially if you use the ccs pads (which I have) they tend to get filled with trapped residue much easier.
As far as the cleaner and conditioner, get the cleaner on sale simply because it's cheaper and conditioner's are pretty optional, As someone else said just prime the pads with the product you are using, I spritz some Distilled water on the pad for it's first use and prime with the polish or lsp.
I'd also say the pads recommended by others is a good start, 2 orange, 2 white, 2 black should cover most situations to start. What size vehicle are you doing as 2 pads might not be enough for a large vehicle especially if you use the ccs pads (which I have) they tend to get filled with trapped residue much easier.