OK, a few questions to deal with here...I'll do my best to work through them!
Walt - good tip on the probes. I believe Rick was talking about meat probes, so I'm not sure if your tip is for SI or Rick. But yes, a high-quality internal box temp probe will be part of the work on a new controller. As of now, the controller probably won't have an internal meat probe - too many points of failure. Most folks prefer their Mavericks, Tapacues, or other thermometers.
Rick & Koze - retrofit will most likely be an option. The controller hooks up with the same wiring as the analog controller, so retrofit should be easy. As you can see from my pics, the controller housing just screws down to the top of the box.
Koze - Yes, buy the current version. It will serve you well as-is, and later you'll have the option of the Auber, and eventually an electronic controller. Use it, love it, now; upgrade later - if you choose. Many owners are very happy with their standard analog controllers. The analogs have the advantage of low cost of replacement, and very good cold-weather reliability. I can personally attest to that. Yes, there are temp swings, but they are consistent and predictable.
Rick - as for the display: Work needs to be done on the "readability," not just making it flashy-looking. The current LCD display is very hard to read. You need good weather-proofing, but the display window needs to be more clear. I'm sure the actual display inside is fine - you just can't read it unless you get close, and at the right angle. I can set my Maverick on it, and read it through the kitchen window, if the remote's in another room.
Hope this helps!