HELP for Transponder Keys, '98 MR2

Hi everyone, been a long time reader and finally decided to make an account on this forum a few weeks ago.
I recently bought a 1998 Rev 5 MR2, car wasn't really cared for by the previous owner, oil was thick and gooey, paint isn't in too good shape etc. etc. etc. The previous owner only supplied one master key, and I was hoping if it was possible to pair another one by myself so that I could have a spare in case anything happened.
 
My car:
-does not have a blinking security light unlike my other Toyota
-has an aftermarket alarm (Python?) system that SEEMS to be connected to two doors, key barrel, and starter motor. Cannot tell if it can cut fuel as well.
 
Questions
- Does my car have a factory immobiliser?
- Will the aftermarket alarm system affect my ability to pair keys?
- Help me find a suitable key (eBay), and pairing instructions?
 
Thanks in advance

Thanks for the reply, I was looking at something like this ▼▼▼
 
Two sets of very different instructions to pair a key :
1.. Copy the cuts of the original working key onto the appropriate
transponder blank.
2.. Enter the car and close all of the doors.
3.. Simultaneously depress and release both the brake and accelerator pedals.
4.. Within five seconds, insert working pre-programmed key into the ignition cylinder, and turn to the "on" position.
5.. Within fifteen seconds of turning the ignition, depress and release the accelerator pedal five times for a primary key.
6.. Within twenty seconds, depress and release the brake pedal six times for a primary key. 
7.. Turn the ignition to the "off" position and immediately remove the key.
8.. Within ten seconds of removing the key, insert the new key and turn it to the "on" position.
9.. Within ten seconds, depress and release the accelerator pedal once. The security light will then flash for 60 seconds and then turn off. When the security light stops flashing the programming should be complete.
10.. Start the vehicle to verify that programming was successful.
 
As well as :
1.Make sure all doors and windows are closed.
2.Insert master key into the ignition cylinder.
3.Cycle the ignition cylinder from ON to OFF 5 times.
4.Open and close the driver side door 6 times.
5.Remove the master key and insert the new duplicate key.
6.DO NOT TURN THE IGNITION CYLINDER ON
7.The new key will be registered after 60 seconds.The THEFT light on the dashboard will go out,indicating that programming has been completed.
 
Wanted to see if anyone's actually done this successfully and get them to give some advice.
 
Problem is, my car doesn't have any sort blinking security or theft light, so I have no idea if any of the above methods will work. Just wanted to see whether MR2s came with blinking lights or if mine was just an exception.
 
-AND
 
I've heard that there are different types of transponder chips in identical looking keys, so I'm not too sure on which to buy.
 
Thanks again, appreciate any advice