I had a similar dilemma a year ago.. I had a few YS120/140 engines from 10 years back, 2 pattern planes, ... I sold it all to get into electric. Very happy I did. It's a new learning curve, so go slow and learn all you can. It can be dangerous if you don't cool things properly and monitor your current draw.. but it's not real hard to figure out and be safe. I think you will find answers to any questions you have just by posting it here. Just look at who's flying electric and you'll see the future. On the LiPo batteries, I flew a 5s3p pack in my first pattern plane (some may not think it was a good one, but it did the job.. a Venus 40) knowing I wanted to get into a 10s3P on a larger motor for a 2M plane. This plan worked well, allowing me to get the basic's down on electric, have a lower introduction cost, which allowed me to use the same batteries in a 2M plane later on. The key (in my opinion) is to not discharge the batteries very hard (>70A) and DO NOT run them until they are about out of charge. I think taking 60% out of the battery over 10-12 minutes is a very safe discharge rate which will allow for many cycles (I had over 200 flights on my packs when I sold the plane - and they were still strong, and still in use today). Today I fly a 2M plane with the newer 5s4p packs, rated at 5300mah.. and I put back in between 2.8A - 3.2A after a Masters flight, Hacker C50-14XL, 22x12 prop.

Good Luck

sc