Do not convert your 1200. It most likely has vertical dropouts, it's aluminum (sorry aluminum fans, but yuck), and that tensioner would give you that same ugly non-pie shaped chainline, and it would introduce more noise into the drivetrain. Wait a while, and while you're waiting, test ride a bunch of track bikes. When you have the money saved up, then buy yourself either an inexpensive track bike (IRO, KHS, Bianchi, etc.), or convert an old inexpensive frame (ebay, craigslist, but get something with long dropouts). Once you've fallen in love, then buy that blingin bike you want.
In the meantime, train your legs.
My $0.02
Edit: I would go the IRO route personally. Conversions aren't my cup of tea.