New And Looking For Advise

I Just Picked Up A 99 4door With 80k Miles Two Weeks Ago. The 245/75 Goodyears That Came On It Have Probably 30-40% Tread Left On Them, Driving Into Town Yesterday A Blew A Tire. I Was Planning On Getting Some Decent All Terrian/ Winter Tire Anyway, But I Have To Make Up My Mind On What To Do Alot Sooner Than I Wanted To. So My Question Is, I Found A Thread On Here That Says The Largest Tire You Can Go With Is 285/75/16. I Know It Throws The Speedo Off By About 5 Miles When Running That Tire, But What Other Issues Has Anyone Run Into While Using A Larger Tire On One Of These Trucks?? Also,the Wheel Ill Be Using Is Not Hub Centric,, I Know Vibration Can Be An Issue, But Again Has Anyone Run Into Anything Else On A Wheel Like That?

Actually, if your stock tire size is 265/75r16, your speedo will only be off by 3.7%, or just over 2 mph at 60. Since this is linear, as slower speeds it will be off by less, and at higher speeds it will be off by more. Here is a very handy web page for future reference:
http://www.miata.net/garage/tirecalc.html

You shouldn't have any issues, other than the hub centric one that is. As long as the tires don't rub, you should be good. But don't underestimate the vibration problem. Anything that causes vibration is bad, and will affect control.