Firstly parts shouldn't be too hard to get hold of. In Europe we can get parts from any Honda dealership when you use the part numbers. They are available on the 'parts manual' section of this site. If they can't help, then Matt and Paul at Tyga Performance should be able to sort you out.
Options for performance tweaks are to fit race pipes, drill a couple of holes in the airbox and rejet. Should get you 55bhp and save a bit of weight. Those std exhaust pipes you have on that bike are really restrictive and heavy.
Next could be to try the above combination with an MC21 flywheel. This give a little more advance, and might get you up to 57bhp.
Lastly the HRC card with a wire splice will get you in the region of 60bhp. but you MUST NOT run the MC21 flywheel with the card. This will advance the ignition too much and you get detonation problems. Check out Tyga Performance's website of the MC28 wire splice info. The problem with the HRC card is it stops the speedo working as well as the oil warning light. These are sometimes useful on a street bike.
I think if you like the look of the '28 and you want the trickness of a smartcard then get the bike.....4-5bhp deficiency wouldn't put me off.