I started with a SW/Meggit 10599 and later switched to a 10611. I've never counted rows. Both were remote mounted, which was not an issue. I've seen multiple approaches to mounting.
There are a lot of opinions about acceptable oil temperature. Mine is that I never want to see 210F, but will accept short excursions to around 205 in a long climb. Likewise I want oil temp within the same parameters given a taxi of any length, or multiple laps around the Ripon approach at 90 knots.
Both coolers were full ducted. With the 10599, I played with ducting cold air to the cooler, bypassing the hot fins in the upper plenum. The supply temperature difference was 16F. It worked, but a larger cooler worked better overall.
Exit ducting runs to a converging bell in the cowl exit. Pressure at the end of oil cooler duct is about 1.5" H2O above freestream static in cruise. Typical lower cowl pressure for RV's is 1.5" to 2" at cruise, with some examples outside those points. My lower cowl pressure in cruise is more like 6", as I run a very small cowl exit. The cooler would not have enough air pressure drop across it without the exit ducting.
http://www.vansairforce.com/community/showpost.php?p=1057297&postcount=197
IO-360 angle valve/CS with standard cowl? Remote 10611 or similar. Parallel valve engines without squirters need less. Fixed pitch needs less.