I suggest you stay with OEM fluids for everything except engine oil and transfer assembly hypoid gear oil. I've found my local dealer responsive to matching online prices, so OEM fluid costs are not prohibitive.
Also, you can buy the OEM sparkplugs on Amazon for about $10 each... which is far cheaper than at the dealer.
Here are some links you may find helpful:
http://www.ridgelineownersclub.com/forums/showpost.php?p=793681&postcount=30
Do not use 3rd party fluids for the transmission (DW-1) and rear diff (VTM-4 fluid). While you can likely use 3rd party fluids for the brakes and power steering, the cost savings are inconsequential so I stick with OEM for those. I also think it wise to stick with Honda pre-mixed coolant too.
You may want to get up-to-date on some of the flaws that some people have experienced:
1) check plug torque (13 lb-ft) for the infamous cylinder 4/5 issue (but since you're replacing plugs, you should be good. While the NGK plugs have a special coating on them negating the use of anti-seize, I've come to the conclusion that since the FSM specifies the use of AS, I put a small amount on the plug thread and use the factory torque settings to tighten. I have to assume the FSM takes AS into account with the torque specs.
http://www.piloteers.org/forums/14-problems/27614-anyone-ever-hear-spark-plugs-backing-out.html
2) check out your radiator/tranny fittings right away. While you're doing the TB/WP/hydraulic tensioner, you might want to replace your radiator at the same time.
http://www.ridgelineownersclub.com/forums/showthread.php?t=53921
3) I strongly recommend a valve adjustment when you do the TB service too. The exhaust valves tend to wear into the seat making them tight... which I think is worse than too loose.
http://honda-tech.com/odyssey-|-rid...miles-less-not-105k-honda-recommends-2726472/
