Welcome from northeast N.J. Your user name reminds me of a custom van I saw in 1977 at a show. It was called 'Penny Pincher' and had over 1000 pennies used as buttons on the button tufted interior and the bumpers were copper plated, as were all the normally chromed parts.
I would go to a few SSR rallies and talk first hand with a couple dozen SSR owners.
I very strongly suggested to Joshvette prior to his SSR purchase that the SSR is a TRUCK, not a Vette, or anything of the like. It rides like a truck, is very heavy (over 5000 lbs loaded) and will NEVER handle like a Vette. As you can see, he did purchase one, and currently seems to be happy with it. (Sorry for putting words in your 'post' Josh) Power is not the problem, as 450-475 HP is fairly easy to obtain with the '05/'06 6.0L.
That being said, it is an eye catching, usually positively commented vehicle to drive.
The best way to purchase one is to find the one you can afford, and post VIN here, so someone can find the history of it. (Not always, but most times it can be checked)
There are several on this site for sale at the moment, six in Arizona that seem like quality trucks, among others. Buying from a Fanatic is not
a guarantee of perfection, but many of the Fanatics take the care of their SSR's very seriously.
You also need to think about how it will be used, as a daily driver, or a weekend cruiser.
If price is a deciding factor over everything else, the '03/'04 is usually sells for less.
Mileage is another factor in pricing. If using as a daily driver, maybe find one with 60k to 80k. The engine is relatively long lived(depending on previous maintenance)
The transmission (auto), to me would be the most likely to fail on a non maintained vehicle (common 4L60E). The clutch on the manual trans truck is a week link, but fairly easy to upgrade to LS7 type.
I know, you probably are thinking that I am stating the obvious, but these are some of the things to be aware of.
Insurance is another important aspect of owning an SSR. Make sure what ever company you choose understands the body part replacement issue and will be willing to pay for New when available, as these parts are very pricey. The grille spear alone is upwards of $600, headlights $400 each, tail lights $350 each(no new ones at GM). Fenders and hoods are available new, but $1700 for a hood and $800 for a fender.
Good luck with your search for an SSR that suits you.