Tires and Lift Kits for 1st Gen

I have a 2008 GMC Canyon 4x4. Just a few questions I need answers to ASAP.
1) I have the stock tires (235/75-15) with Vision Warrior wheels. They have a 0" offset. I was wondering if anyone knew if you can fit 30s on stock height? Is there any rubbing? And I have aftermarket RDJ fender flares since I already have the wheels sticking out. Will 30s cause mud and snow to be thrown up the sides of the truck, even with larger fender flares? I'm thinking about getting some BFG KO2's.
2) I've also been considering getting a lift kit for my truck. I'm on a budget so it has to be under like $500. I was looking at getting the Zone Offroad 3.5" x 3" combo lift kit but I don't have the knowledge or time to do it myself. I've asked a few local shops and their asking at least $1,000 to install it due to the liability issues with the body lift. I'm thinking about getting new torsion keys and getting an add-a-leaf which will give me like 2" of lift, which I originally wanted at least 3", but friends and family have told me that the ride will be stiff. It will feel like driving a brick around town. Is this true? They've also told me that it can cause a lot of problems starting with the shocks and the driveline.
Please let me know. Feel free to send pics of your truck too. Thanks!