If that's supposed to be a list in order of value to the rider's performance, I put clothing second, maybe a multi-hour saddle third, learning to eat and drink on the bike fourth, fast tires fifth. I put nice new bike of whatever material last, and nice wheels even below that. What you need to get fast is miles and hills. Clipless sure makes the most difference there. All the rest of it is secondary. It doesn't matter how fast you go unless you're doing competitive group rides. It only matters how long you can stay on the bike and how well the bike extracts energy from your body. That's what will make you fast, over time. Once you're fast, then buy the fancy stuff. By then, you'll know what you want to spend money on.
For electronics, all you need is a wired Cateye computer, maybe $30. For effort, an $80 HRM will serve one well for years.
In the OP's case, having presumably already done all of the above, yeah, the next step is a good carbon bike (should have already had the clipless). I'd agree that an aero fit to that bike is a big and inexpensive performance gain, but then I'd put tires ahead of wheels in value. I still don't run carbon wheels. In side-by-side coast downs, position beats everything, tires are next, wheels last. So far I've never had a carbon wheel bike beat my deep section alu rims with CX-Rays. Besides, I run rim brakes. If the mid-range carbon rig comes with rim brakes, I'd stick with the stock wheels until they're worn out. I admit to running tires same width as the rims on my home-builts.
Somewhere in there, I'd put customizing the new bike's gearing to better match the rider to the riding in their area - if necessary.
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