i would apply as many coats of the clear as they suggest. then if you can keep spraying it with decent results i would spray on one or two extra coats. give it plenty of flash time between coats, don't rush it now! let it hang someplace WARM, with plenty of fresh air, for a few days before sanding.
this will give you enough clear to wet sand and polish. wet sand the finish with at least P1000, P1200 or P1500 will be easier to polish, using a block like this: http://www.ebay.com/itm/NEW-Wet-dry-...item41712e2626
or like this:http://www.ebay.com/itm/Flexible-San...item5653d26208
when sanding use as little water as possible with a drop or two of dish washing soap in it. the idea is to just level things off, removing any bumps, before buffing/polishing. if you skip this step and go straight to polishing you just end up with shiny bumps.
the one site you linked to has Meguiar's and they sell what you need to do the sanding as well as the polishing