Bruce: while I have the '22, I hope a few of my comments may help you.
First, the twin 430 installation allows crossfeeding of flight plans and such. Some people set it up so #1 talks to #2 but #2 does not talk to #1. This allows for 'what ifs" without risking changing the flight plan until you want to. You can override the default for #2 to send the flight plan you just worked on to #1 by hitting about 2 buttons.
Secondly, I think the Sandel is overkill. So far, it has been very reliable (better than many comments about the HSI). I have use few of its more sophisticated functions over and above the displaying the stormscope and the basic HSI functions. I wish it was brighter and the polarized glass makes wearing polarized sunglasses difficult.
The Stormscope also displays on the ARNAV, so I use that for the 50 -100 mile ‘tactical’ range and the Sandel for the 100 - 200 mile ‘strategic’ ranges. (I partly do this as my wife lights up faster than the stormscope on the first hit. Even if it is 200 miles away and 50 off our flight path. Keeping the ARNAV on a shorter range allows me to see the big picture without unnecessarily alarming my wife.) I could live without it displaying on the Sandel.
Third, having twin 430’s allows you to only learn one GPS’s operations. I’m sure the second Garmins in the “B” config is similar, but when things are rushed, the easier the better.
Bruce, you live in FL - the land of the PM thunderstorms - you need the stormscope!
The 3 blade props look better, but do you wnat to pay for it? It weighs about 15 - 18 lbs and is located way out in front. From what I hear the SR20’s tend to be front heavy anyway.
The S-tec 55x is fantastic. If you have a choice, go with it. The altitude pre-select is also very good and I’m not sure if it is available or what the cost, but I would strongly consider it as well.
I also don’t know the cost of the HID light, but given the trouble others have had with the conventional bulb, I’d go with that as well.
From my perspective, here are the priorities I would place on many of the upgrades or options in the “C” package:
HID Landing Light
3 blade prop (yes, weight (useful load) is very important to me)
Just my $0.02 worth. YMMV.
Marty (sorry about the ‘annonymous’ user name - I’m really Jatiii)