cheap window reverse cycle ac build

[jeff5may]

Prior to opening up this can of worms, I did some ebay shopping. The stuff I picked up:

RANCO V3 REVERSING VALVE/LESS COIL - $12.00
JARD TRANSFORMER, PRIMARY VOLT:120, SECONDARY VOLT:24, VA:20 - $5.00
Ranco Invensys L30-83 Solenoid Coil 24 VDC for V1-V12 Reversing Valve - $5.00

Robertshaw 300-201 1 heat/ 1 cool digital thermostat - $1.05
(EDIT: This thermostat will be replaced with a HEAT PUMP THERMOSTAT since it makes the unit short-cycle in heating mode under certain conditions.)

ICM 315 Defrost Control Board works on any brand heatpump FREE SHIPPING - $3.75 and it comes with a thermistor!

I'll be looking for a txv the right size to replace the 3/4 ton one I harvest from this unit...
But guess what? I might be able to use aforementioned txv in the other unit! Maybe...

For now, I've got questions.

1. The reversing valve I scored is rated at 3 tons max. Will it work with my 1 1/4 ton compressor? If not, what can I do to help it work?
2. What is the best practice in plumbing a reversing valve? Special routing of piping, etc.
3. Should I even bother with a txv? The unit has 2 short cap tubes... how much would I gain going txv on the outside coil versus leaving the cap tubes? I would like to get down below freezing on this unit. The txv I just found in this unit is rated to -40*f.

For now, I'll be waiting for my items to ship. Meanwhile, I'll figure out how to wire this beast with what's coming soon.