Cruz,
Nice to see you are getting into gas, I think you'll like it. I went through the same thing you are going through just a few months ago. I wanted to get started into gas and had no knowledge and no one at my club flies gas. I spent alot of time on this board reading alot of posts until I felt confident enough to make a purchase. I bought a Zenoah 62 that was lightened by RC ignitions. The way it was lightened was by converting it to electronic ingnition. I feel that this is a must (electronic ignition). Most manufactureres now have at least some if not all their engines running on electronics. Going to electronics does make the engines lighter and easier to start but requires an extra battery and a kill switch. All of the top pilots using gas fly electronic ignitions. Another thing to consider is the chances of RF interference between the gas engines and your radio. there are ways to isolate the interference and there are tons of posts on this subject here to read. I am not going to state my favorite engines nor what brand the other two I have since purchased, I leave that up to you when you go through RCU. here you will find opinions pro and con on virtually every mfg. What I do recomend besides going with an electronic ignition is to buy from a reputable supplier who can not only answer your questions and who also gives you good support down the road ,especially your first gas engine.