Just to clarify, are you intending to try to get a BMW scholarship to get in or actually planning to just enter the Formula BMW Asia series?
If you're going to attempt to get the scholarship I'd focus on that for the moment rather than trying to get a sponsor (or pick a visor colour). Given that scholarship covers around 35% of the season's running costs I would be trying to get that 1st, otherwise you're looking at generating around $150,000US to do the series (based on 2007 figures).
You'll still need around $100,000US with the scholarship, but you'll get help from BMW with acquiring sponsors should you be successful.
Basically Nico Rosberg got help by entering in his dad's team, Mansell's kids are doing the same. Vettel had been karting since he was 8 and BMW probably have an option on him should they want him.
All in all, I wouldn't say this is the easiest, or cheapest formulae to start in for a complete novice, and the rewards seem to go to drivers that have sound backing to start with.
If you do get in then I wish you well, but it sounds a bit more involved than your post makes out.