I'm not sure which movement to get yet, still trying to figure out which one is the best/most reliable. Do you have any recommendations on where to start?
OK well, just like regular watches, reps can be repaired.
The 2813 is the cheapest movement, these can simply replaced for $15 from eBay.
The 3135 is difficult to repair and parts are not readily available, although this movement is a clone of the Rolex movement, so more gen-like. Ultimately the whole movement can be replaced for £200+ from eBay.
The 2824/2836 is a clone of the Swiss ETA movement, is reliable and is easier to repair and parts are available and ultimately can be replaced for about £50 from eBay, or you can swap in a gen Swiss ETA or Sellita movement.
I would recommend the 2824/2836, depends how close to gen you want to be.
Of course the next step is finding a rep-friendly watchmaker to service/repair your watches (should you need it).