I'm not so sure an HHKB would be my preference in a KB for one who writes for a living; although it may be great for people how write code.
The FC660C is probably a good fit for you if you're looking to go small.
- It's plate mounted like the Realforces (and thockier than the RF by some accounts)
- Standard Layout (No traditional 6 cluster but it has a dedicated Delete key)
- Cheaper than both the Realforces and HHKB
The biggest challenges I had when going over to the HHKB layout was:
1. Control key is where the Caps Lock button is - copy paste functions become less than second nature
2. Backspace key is where the Backslash key is - This drove me crazy at first
3. "6 Cluster" in the second layer (Had trouble adjusting to hitting Home and End especially)
I may be somewhat of an oddball because the arrow key combos didn't really bother me, and that seems to be what throws most people for a loop when they adopt the HHKB layout. I actually really like the way the arrow keys work on the HHKB. It's actually the Home and End key combinations that are difficult for my brain to process sometimes. You have to kind of reach for the Home and End key combos where the arrow keys sit naturally under your fingers.
Took me about 3 weeks to get used to the new layout and now I switch between my 87U at work and my HHKB at home seamlessly. I think there are advantages to both layouts, and I think learning new ways to do everyday things and flexing your brain outside of its comfort zone keeps life interesting.