They still offer the g-sensors last time I looked. I've already tried one on my SSI-4: give it voltage, ground, and read the output. They are instant response, and only need the extra resistors/capacitors if you want an ultra-clean output. They're the cheapest g-sensors you'll ever find (~$15 IIRC), if you can't get samples at least. :somb:
As for the MAP sensors, they range from $11-16, and usually $6 for shipping. I should have my DIY MAP Sensor write-up posted soon, so you can have a bolt-on 4bar MAP for a FRACTION of the cost of an Omni/Hondata 4bar.