ORIGINAL: xDennis
These are my main concerns:
1) Is the engine reliable, if i get into minor aerobatics and Roll, I don't want a staller..
This issue relates more to getting the tank at the right height, and making sure the exhaust pressure works, etc than to the engine.
2) Is the engine easy to tune. I live about 10mins from the LHS and could bring the engine if i have any tuning probs but I would rather do it on my own.. So i would like an engine that isnt that finicky.
The reports from people in RCU will give you one source for identifying engines that are not finicky. The people at the field are another. However, it's important to understand the difference between a finicky engine and a person who can't tune right. Over time you'll probably notice that certain people are always "messin wit their engines". Others just show up and fly. You also should rely on help from your instructor. Early in your training he should teach you how to tune the engine.
3) Longevity... I suppose if you treat any engine the right way it can last forever though..right??
Unfortunately, not entirely. Parts do wear out. Quality control problems slip into production runs. Manufacturers go cheap when they order parts such as bearings. New, and unproven, designs end up being bad ideas. However, in general, if you stick with the well known brands and treat your engine right, it will last a long time. I still fly the OS 25 FSR that I had in my second plane, sometime in the late 70s.
5) I don't want to out grow my engine in a few months.
You're looking at a good size range.