Which remote to buy for factory keyless entry?
 

95 XJ with stock factory keyless entry (i.e. small black dome on roof (headliner))

Which remote should I buy? I assume these are pretty simple so should just a basic infrared remote be able to pair with the system?

How about something like this: https://www.amazon.com/Keyless2Go-Ke...s+entry+remote

It will cost you more for remotes than it will for you to install an aftermarket keyless entry system.

For example: $60 for a remote
http://www.ebay.com/itm/OEM-Jeep-CHE...lXhUeZ&vxp=mtr

vs $39 for keyless entry and remote start
http://goo.gl/2fWBTd

or $17 for just keyless entry
http://amzn.to/29MC5SB

And that link you posted is for Ford RF remotes. No way to make that work.

On my 1990 XJ I have what looks like just a regular universal remote that was programmed to work with the keyless entry system (and it does). I know for 97-01 you need a special remote and a dealer to program it, but for 96- I believe the system is much simpler, and can be programmed like this: (don't quote me on this though)

From the internet:
"Up to 4 transmitters can be programmed into the receiver at any given time.

All transmitters to be used on a vehicle must be programmed during this procedure.

(1) Open the driver’s door and leave it open during the programming process.

(2) Move the mechanical door lock lever on the driver’s door to the LOCK position.

(3) Insert the ignition key and turn it to the RUN position. (Do not start the vehicle.)

(4) After turning the ignition key to the Run position aim the transmitter at the receiver and press the LOCK (right) button for 5 seconds. Once the receiver accepts the programming the door will unlock.

Move to Step 5 If you have more than one transmitter you are going to use with this vehicle. Move to Step 6 If only one Jeep remote is used.

(5) If additional transmitters are to be used on the vehicle each must be programmed during the programming sequence. (Up to 4 transmitters can be programmed to a vehicle) To program additional transmitters Return the mechanical door lock lever on the driver’s door to the LOCK position and aim the next transmitter at the receiver and press the LOCK (right) button for 5 seconds. Again when the receiver accepts the programming the door will unlock. Repeat step 5 until all transmitters have been programmed.

(6) When all transmitters have been programmed to the receiver, the ignition must be turned off and back on within 20 seconds after programming the last transmitter. When this is done, only the transmitters that were programmed to the vehicle during this procedure will operate the locks."

Can anyone confirm that those steps above work on pre-97 XJ's?

Your 90 either has the factory keyless entry, in which case you can test those instructions yourself by programming your 1995 to accept the 90 remote using the instructions you posted,

or, more likely,

Your 1990 has an aftermarket keyless entry system like the ones I posted. There is no such thing as a universal remote that would work with a 1990 Jeep factory keyless entry.