None of the N/A mods will do a lot for you by themselves. Doing them all will get you to 300ish to the wheels. As explained above, a blower will get you well above 350 by itself. So how much money do you have? If you really want some hp I would suggest working all summer and saving up for a blower. I went the N/A route, spent tons of money and then got a blower. None of the N/A mods compared to the blower. It's the best bang for the buck, besides nitrous.
With all that said, nitrous is cheap/easy hp. Gears are a great mod to do for a SOTP feel. I know you said you have exhaust but if that's only a catback I would suggest an O/R midpipe, depending on your emissions testing regulations in your state. I bought Mac ceramic longtubes, about $450, at that time I wasn't ready to do the instal myself. It's pretty tough if your not set up with proper tools or experience. I forget what I paid to have them installed but I think it was another 300 or so. That was another good NA mod. Good torque gains. At some point you probably want to do a TB/Plenum with CAI. I just didn't feel much from them but together with a full exhaust they will help. The other option is a programmer such as Predator or SCT. They can change your speedo for when you do gears and you can bump up the timing and run hi test fuel. I really noticed an increase in throttle response with my predator. Heads and cams are another good mod. I would suggest VT or MPH. Good proven gains and they will work better with intake and exhaust mods. I would recommend stage 2 N/A cams from VT and you can drive without a tune but tuned is much better but also more $. As far as the under drive pulleys people are pretty split on these. I bought Steeda UDP's, which are considered one of the best, and they made the car rev faster so a slight noticeable difference. As long as you install them correctly there isn't really any problems with them. I just took mine off when I put my KB on so if you want a used set, shoot me a PM.
Well I hope this helped. As far as handling goes, I suggest taking a look at MM's website. They have boxed kits that makes sure everything works well together. They are a very reputable company and know thier stuff. Keep asking questions and you'll find what your looking for. Stangnet is an awsome site with some really good guys so welcome and good luck.
-Steve
