A rear disc conversion is really simple. If you can find a 92-95 Civic with disc then it will obviously swap in. They are a little hard to find. You can also use the alternative, 94-01 Integra. Remember that 94-01 Integra's have the exact same suspension as our EG's. Their brakes are an upgrade and work great for our light hatch's. I am in the proccess of collecting for this exact swap.
I however am doing the front and the rear. Integra's have 262mm rotors and larger calipers. This is an upgrade from our 242mm rotors and smaller calipers. Their master cylinder and brake booster is also much larger then ours and will also bolt up with minimal modifications of the brake lines. I will give you a list of what you need and your options depending on how far you want to go.
Rear Disc - Integra or Civic disc trailing arm assembly. This is the whole thing. Rotor, hub, bracket, caliper, and trailing arm. You can seperate the hubs but it is MUCH easier to get the trailing arm assembly and bolt it up. This also gives you a great chance to replace those old bushings. You will need the brake cable from a 92-95 Civic with rear disc. This can be found at any parts store. You will also need a 40/40 proportioning valve from a rear disc EG civic or 94-01 Integra RS. This valve is on the firewall and has the hard lines from the master cylinder running right to it. The rear disc valve will have 40/40 stamped in the side. Some will argue that this valve is not needed but it should be used to make things function as factory. Here is a picture of my GSR rear disc trailing arms.
Font Disc - As I said before that Integra brakes are a definate upgrade. Like the rears they simply bolt up. You just have to get the spindle and brake assembly together. You can change bushings, balljoints and tie rod ends at this time if you like, but it's not necassary. Here is a picture of the assembly. This picture shows the upper contorl arms attatched also. You don't need this, it just came with the one I bought.
Options - There are several options for a Master Cylinder and Brake Booster when doing this swap. If you are just doing the rear disc then I would recommend upgrading to a 15/16" MC from a 91 Civic EX Sedan. This MC simply bolts up with no modification whatsoever. This is a definate upgrade from your 13/16".
If you decide to do the Integra fronts also then I would recommend an 1" Integra MC and booster. This is a little more involved but the results will be much better pedal feel and braking power. All 94-01 Integra's with ABS have a 1" MC. The MC and booster bolt right up to our cars. However, you must modify the lines coming from the proportioning valve. Because the ports on the MC's are placed differently then you must bend the lines to make them line up. This is not hard and is a minimal task for the performance gained. I would also recommend an MC from the 98-01 years in particular. These MC's have the same flare size and nut thread as our cars. This will keep you from needing an adapter. The 94-97 line and nut size is slightly different. This is a picture of my JDM ITR master cylinder and booster.
Hope all this helps. It's always good to remember that 94-01 Integra suspension is the same as our 92-95 EG's. This is great if you have a DX with no sway bars, simply swap in the Integra LCA's front and rear. Baam, instant sway bars.