Sounds like you have the extruded aluminum handles, which is good. It means that chances are, you have framed panel doors, which would make sense, because it used to be the only type of door available from Sub Zero. Unfortunately, I don't think you can change the extruded handles you now have for the bar pulls that the factory-built stainless steel models come with today. The extruded handles attach to the edge of the door, and if memory serves correctly, are a part of the frame that holds the decorative panels in place. The bar pulls on the factory built SS models are attached to the door fronts at the factory. Anyway, to answer your question, framed panels are flat panels that are held in place by a thin metal frame that goes all the way around the doors along the edges. If you have plain flat panels held in place by an aluminum edge all the way around the door, then you have framed panels. Changing the panels out is a simple matter. You simply remove the screws that hold the extruded handle in place. Once you remove the handle, you should be able to slide the old panels out. Then, just slide in the new panes and replace the handle. You can find illustrations and instructions pertaining to framed doors on current Sub Zero models in the installation guides available on the Sub Zero website. The frame system is still essentially similar to what you have on your refrigerator. The link below will take you there. Scroll down to page 12 for info on framed panels. Here is a link that might be useful: Sub Zero Design Guide

I could certainly be wrong but from the sound of your post you sound like someone who has "aspired" to have a SubZero fridge not necessarily for a functional reason but to have the brand. It sounds as if you're going all out - two Miele dishwashers, etc. - so why not just go for the SZ? If you think about all the people who have been keeping their food chilled without investing in SZ, there has to be something people "value" about SZ other than it's functional ability to keep food chilled or frozen that would make them pay the premimum price. Could be appearance, appeal of saying you have the brand, etc. In any case if you want one and want to spend the $ go for it. It seems you can count on repairs with any brand these days - kind of like luxury auto brands. Just because you spend alot doesn't mean it will be trouble free.

FYI - I grew up with a 500 series all freezer. It's icemaker gave up the ghost in the 70's and never could get fixed. Got an ice machine in the bar/pantry and didn't worry about it. A new ice maker will run you $100-200 + install and may not solve the problem. A door gasket will be $75- $125 if you can get one. A wire bin $60- $125 again if they are available. A complete overhaul of the sealed system will run you $500-$1200 but should last another 10-20 years. FWIW - SZ still makes those 36" all fridge all freezers. However, they are different sizes now. SO, before you go building the cabinet space to fit these you might want to consider what is going to go in there and its size before you commit suing or repairing these. At the least you need to accommodate for easily alteration - usually making the space taller.

IF SZ does not sell them frigodesign.com can custom make them for you plain,pattern,copper etc. Not too expensive either. Here is a link that might be useful: Frigo Design