Don't think a single 30 would be pleasing at all. Probably hard to get on plane and lucky to get top speed of ~20. Probably would troll fantastic. Anyone ever do twins on a 16? My son in law asked me that a couple years ago and I don't know if I've ever seen that except on April fools . Joe's right, if you did go with a 30, it would probably be a hard sell. Allot of people who aren't familiar with these boats are surprised they run with a 40-50. My 50 ETEC pushes mine about 30 with just me, 9 gallons and fishing tackle, add a fishing buddy, and double the fuel (for trips out to Lake Michigan and it drops to 26-27) bot rides a better in a chop. A side note on the ETEC, I had a 90 on a different boat and it trolled well. My 50 is not particularly smooth. I troll with a Yamaha T8 which is great on gas but with the power tilt and trim and electric start is heavy. I've got a friend with a Yamaha 50, 4 stroke that trolls very smooth. Might give you what you're looking for, have better re-sale and let you open it up on days that are really calm. Good Luck