so with a shot heater valve I've decided to finally replace teh major elements of my aging cooling system. However, I'm not sure which manufacturers I should go with on certain parts, or which parts I should pck up in certain instances:

1) Thermostat:
The car is a 1985 745t m46. Which thermostat below do I want? I think I want the 87 wahler, but I really have no idea.
Thermostat Calorstat87ø $15.93 $7.40
Thermostat Wahler 82ø Wahler $15.93 $8.49
Thermostat Calorstat92ø $16.76 $7.11
Thermostat 71øC/160øF Wahler $15.93 $8.57
Thermostat 92øC/197øF Wahler $16.76 $8.15
Thermostat Wahler 87ø Wahler $15.93 $8.45

2) Heater Valve:
The following have extreme price differences... I've seen Mission's name around, do they make solid parts? Who is 4 seasons? I'm assuming the expensive one is from Bosch or something, but I would think it would say so in teh parts list. Obviously I'd like to save $50 and go with the Missions part, but I don't want it to crap out on me.
Mission Trading Company $66.01 $13.16
4-Seasons $66.01 $15.03
Heater Valve $66.01 $54.35

I'm also picking up a Nissens copper 3 row and a new 150kpa cap for teh expansion tank.

Thanks in advance for the help.

-rt