Personally I think most on this forum put way too much emphasis on plugs/wires brand. But that is just my opinion. I'm sure they will bust my chops. The disco did not come out with magnecor wires when it was stock and it ran just fine. Basic plugs/wires if in good shape should not cause misfires. They may not perform as well as mags or bosch plats but at least they should not cause misfires.
Your issue is not plugs and wires unless you have them out of sequence. You need to figure out where your losing coolant and verify cylinder pressure.

Ask your shop to perform a coolant pressure test and also compression tests on each cylinder. Were the heads machined/resurfaced when the head job was done? If this is a good shop they should already be doing this for you instead of you trying to figure it out.

Any codes?

i have P0308, P0306, P0305 (the shop i just took it to added this one), P0447, and P1300.

What was the final outcome?

The final outcome is that nothing was solved and I still have all these problems. I haven't driven the rover in 2 months because I can't get it registered with all these codes in the system. Plus it will probably catch on fire if I continue to drive it.

have you had it pressure tested? are you losing pressure in any of the cylinders? you need to have it checked to figure out where the problem is.

So you have misfires on 5, 6 and 8. If you are sure your wires and plugs are good then get a used set of coils and see if that is your problem. P1300 is a generic misfire code and P0447 is a Canister Vent Solenoid (CVS) Unit code, replace it.

First I would have to get in the thing to be able to actually do any work on it. Since some genius engineer designed the vehicle with only one key hole which is prone to breaking I cannot get inside with my battery dead. Disco mike told me to try jumping it at the positive lead from the starter but that did not work either. So now I either have to break a window or pull the hood release cable somehow.

if you can get into the truck simply pulling the plugs will tell you a lot, any plugs that have a very clean or rusty electrode will be an indication of coolant being ingested in the cylinder.
My guess is a cracked cylinder or two but pull the plugs first and see what they say.
It could also be a cracked head. Was the engine ever overheated?

yes. it was overheated a few times.

Bahh Dum Dum............... might be time for a new engine.
Pull the plugs first