OpenBSD Blade 100, SATA, sili(4), and 'break' or 'STOP-A' from Linux or OS X

Hi.

I've gleaned much from y'all over the last few years, and am hoping that
your collective knowledge may help me in these several specific troubles.

Has anyone firsthand experience with a solution to a usable (PIO4 or
better, UDMA is much preferred) >120G disk of SATA variety to help an
otherwise pretty good Blade 100?

Or even PATA (as above, obviously via add'l controller)?

Disk need not be / or /boot !


Has anyone a Linux or Mac OS X terminal emulator hint, tip, trick, that
might help me with sending the ever-sought 'STOP-A'?  I performed a
'set-defaults' and 'reset-all' without thinking it through.  Now
Blade-unhappy-spare wants a net-boot.

Google is turning up many suggestions, none working for me.  Linux
solution most helpful at the moment.  Even better if it doesn't involve
VT-52 emulation.  <g>

Finally, is there a recommended document about boot order and dual
booting?  I've an urge to make the Blade behave in booting rather
PC-like: if CD boot CD, else if HD boot HD, else run monitor.  Addl'y
I've Solaris and I would like to run that once in a while.  AS so long
as I'm asking, I'd ask for a boot-menu-like construct that offered
choice of OS on a dual boot disk, and defaulted to my choice after a
certain amount of time expired.

I realise it's a lot of questions, thank you to all who consider them.
(I don't know if this applies, but any personal replies will be
summarised back to the list.)