Hi kbeaub,
You can see some of my thoughts about Novosbed in post #7 here.
The choice of an adjustable bed is a preference so only each person can answer for themselves whether or not it’s worth it. For those who like the features and options they can provide (sitting up for watching a movie, working, or reading, massage for those who like this feature, or for elevated sleeping when suitable for those who would benefit from this) … and I’m one of them … it may well be worth it. For those who wouldn’t use the features … it wouldn’t.
I personally have one not as a necessity or need but as a “luxury” which both of us enjoy (mainly for watching movies, reading, working on the computer in “relax” mode, or the occasional meal in bed :)). You can see some adjustable bed comparisons in post #2 here and the links it contains.
If you and your DH would want to use the adjustable bed in different positions (such as one reading and the other one sleeping etc) or if one of you has medical needs that would benefit from a different sleeping position from the other … then a split king mattress may be a good idea. If not … the adjustable bed will be split king anyway (they don’t come in a single king) but a non split mattress would eliminate any issues from having a split in between two mattresses as a tradeoff for the lack of individual adjustment. Again … this would be a preference choice and only you would know which was best for your circumstances. the remotes can be st to operate both of the split king units separately or together.
While I may not be able to narrow down your mattress choices to just two … if you go by the memory foam list in post #12 here (along with Novosbed) you will at least have eliminated many of the worst online choices and you will have the means to make meaningful comparisons between them based on their specs (which better manufacturers or retailers will always provide) and on any other differences in service and options available between them (along the lines of post #46 here)
I would narrow down your choices to the one mattress at each manufacturer or retailer you wanted to consider (if you wanted fewer options you could always include just the ones who were members here) and then choose between your “best” choices at each one based on the quality/value of the mattress itself, the options provided both before and after the sale by each merchant, and on any of the other objective, subjective, and intangible considerations (including how you feel about talking with each one on the phone) and make your final choices between them.
In terms of the adjustable bed … at least your list of sources is narrowed down to 3 
Hope this helps.
Phoenix