The make of cans you decide on are down to you and your tastes/cash flow!
Many Duke owners would not think of putting anything other than termi's on the pride and joy. There does seem however to be a growing number of suppliers willing to produce similar products for a fraction of the cost italian carbon! Check out places like tecmoto or JHP for alternatives...or look in the weekly/monthly mags for second-hand units. Place a post in the market section of this board...second-hand termis are often traded about for good money.
As for the chip, I'm no expert, but if you buy termi's, they should come with a chip...in fact if you buy a different make from any reputable outlet, you should get a chip with them (I know you do with JHP or Arrow cans). You may find that the bike 'appears' to run fine without changing the chip...but it may well be running a little lean(?) and may be doing some unseen damage even if it appears to be running OK.
Some find that even after changing the chip over, the bike still does not run smoothly, and the only way to really get over this is to take it somewhere to someone who knows (ie JHP/Conerspeed(Nelly)) and who can spend time and has the diagnostic equipment to sort it.
But definately do it...the sound is sublime
[Edited on 27-10-2003 by Harv748]