H1 test drive...Issues!!!!!

[Indy]

I'm shopping for an H1, and I've got some questions. I test drove a 2000 H1 today, and I think it had some serious issues (but maybe these things are normal, so please enlighten me). Biggest concern was some severe rocking back and forth when coming to a stop. Seemed like the gearing in the hubs was very very lose. The H1 rocked back and forth at least 4-5 times when coming to a stop, by about 1-2 inches. Felt like I was on a boat. The sales rep said he's driven lots of Hummers, and this is very normal. Well, it didn't feel normal to me...
I have some service statements, in which it states:

...all 4 reduction boxes are so loose they need to be serviced and overhauled gears need to be tightened up...

Secondly, front shocks were leaking bad. How much are replacements?
Also, it had a replacement engine done this year. The engine was a rebuilt 2000 engine from GM. Do you think it might be affected by the #8 cylinder problem?
Rust was also very apparent on the body (lots of rust bubbles). Is this normal, since I thought most of the chassis was aluminum.
Any insights would be much appreciated. Thanks, Indy