Bipes in general aren't a good starting plane. For several years all I built were bipes and just setting the incidence on the flight surfaces can be a thrill.
There is also a reason they call trainers trainers and most people really require a trainer and instructor. You can learn to fly without one but it will cost you a big pile of money every time you crash.
John has the right idea, in my case I used the Senior Telemaster but it's almost the same thing. Big easy to fly and build airplane.
Engines, years ago conversions were a great idea, today not so much but they can be. One buddy of mine was converting Royobi engines, the brush cutter came with two sizes and he figured out the bigger model and used them. He and the club members had a connection at the local dump and got them about this time every year when people tossed out the cutters. They also had an on line place to get the new carbs for RC use. They were cheap and fun but today you have DLE engines out of China that are better and easier to get and use.
It's getting a bit late in the year but you can still go to a local club and find an instructor with a trainer that they use so you can learn to fly for the price of your fuel.
Model Airplane News plans or Airage has several plans for the SE. I built the sister ship, the Fokker D-VII a couple times. The planes were designed for RC and not something you just enlarged.
You just seem to want to do things the hard way and you will be disappointed with what you get. You know, the Right way, Wrong Way and the Army Way. The plans in MAN have the plane in giant scale and the smaller 40 size that just uses a nice .46 engine. Give the plans a look.