micro chipping a cat that travels alot with the family...?

Hi,
I want to have my cat micro-chipped but I have some concerns that there are different types of chips and scanners available across the country (USA).
I have always traveled alot of weekend road trips and my cat has always come with me for these past two years now (since he was only 7 weeks old), but now I just married into a military life so my cat and I could be following my husband all over the country.
Because of this I need the most effective nationwide system, something as universal as possible. Granted I'm not expecting to loose my cat any time soon. FYI: he's a strictly indoor cat and he does wear a collar with ID at all times. When we do go outside, or on road trips, he wears a harness and leash. I just want to be best prepared in case the worst should ever happen.
I've heard good things about HomeAgain, however I want to be sure of that I'm getting what I need when I make this decision:
any websites where I could do my own research would be greatly appreciated.
Thank you!!

we use home again chips at the clinic where i work. we have had pets come in that had different chips, and our home again chip reader will usually read the chip name. for example, a dog came in that someone found, when we scanned it our scanner didn't read a number but a name: avid. avid is another microchip so we sent the people down to animal control who has a readers for all the different chips. my guess would be whatever chip you use you will be ok, if you cat is found someone will have a chip reader that will read your chip.
by the way good job chipping your cat-- many many pets are lost going on trips with owners and never found.

Hi found this site hope you find it of some use, and good luck on your travels, better to be safe than sorry :-)

http://catszone.blogspot.com/2007/03/microchip-your-cat.html