Enhancing my performance

[TheMattHatter]

Well, summer is finally here and now I have the time to make the money to purchase upgrades for my car and to work on it and install them. I drive a 1991 MR2 Turbo and I already have a lightened flywheel, TRD short-shifter, and a stage2 high-performance ACT clutch with HD pressure plates. I want to increase the HP of my car this summer while not going way overboard on the money spent, hahaha, I know. I understand saying those two things together usually brings a sigh or a chuckle since that is a definite have your cake and eat it too scenario, but, what I was wondering was what are some upgrades people can reccomend to enhance my performance, and not only power handling as well, that can be purchased, and maybe installed since I am good with cars, but not great and have never worked on a mid-engine car or an asian automotive. I am hoping to make about 1,000-2,000 this summer which I can put into the car and was wondering if I can get some sugesstions and maybe also brief installation instructions to help me out.
A few questions firstly though:
1) Exhaust, I would love to update the entire exhaust system but don't want to move away from the dual-exhaust since that's what the car has already. I understand buying a new dual-exhaust system costs a pretty-penny and isn't too easy an installation and I was curious if anyone knows about how much HP a decent, not amazing, exhaust system would add as well as whats the lowest I could find an MR2 dual-exhaust for, or if there any that are reccomended. I would love to enhance my engine sound.
2) Blow-off valve. What's the advantage of this exactly? I understand what it does, to a degree, but not entirely and am curious if this is a smart upgrade or if it's actually kind of pointless.
3) Intake. Should I upgrade the air-filter to a TRD or K&N or get an entire intake system set-up? I was tempted to just put on a ghetto panty-hose intake on it since it's a cheap rig-up and has its advantages, but I also understand that the panty-hose intake rig-up isn't good for the car and is a very very cheap and almost laughable upgrade.
4)Should I bother with lightening up the car at all? It's already light and I don't see much that could be done to it to lighten it up without taking away from the class and style that the car has naturally. The actually classiness of this vehicle was one of the reasons I purchased it originally, especially since it is a t-top model and black on black beautiful.
5) Any other ideas or suggestions? What have you done? Would you reccomended upgrades springs/struts or is the handling improvement not very noticeable on this car? How about an LSD kit?

Any input would be greatly appreciated and helpful! Thank you!

P.S. Side-note, my e-brake isn't working, I pull up and it resists my pull a bit like it should, but it wont stop me for anything or anywhere and this isn't good seeing as my driveway is a hill. Also, my turbo-timer keeps the entire engine running for 1min and 30sec after I turn the car off, which means I usually have to stall the car out on purpose on a hill to prevent rolling, and thus this defeats the purpose of having the turbo-timer, did I install this wrong? Is my ignition or starter messed-up? Anyone else have this problem? Or is this the way the turbo-timer is supposed to work?

[MR2Driver]

For power modifications: Power Primer

For all available exhausts: MR2 Exhausts

On blowoff valves: JH's BOV Article

If you have anymore questions after reading the primer, then ask. Try and be specific.

[TheMattHatter]

Many thanks for those awesome websites. I have them all printed out and am going over everything listed in them, the info rocks and hopefully I can start upgrading my vehicle shortly. The power-primer website was especially helpful and very awesome, thanks for linking it for me!