Waaaaaay back in high school I wanted to be an aeronautical engineer so I read everything I could put my hands on. One of the books (remember those?) "Design for Flying" was written by David Thurston. In that book he stated that almost without exception the ratio of stall to top speed will not exceed 4:1.

So for a 50mph stall you get a 200mph top end. What do you know, there's a Van's RV right there. Over the years I've seen published numbers for planes and regardless of what the design goals were, Thurston's ratio has proven correct.

To exceed that ratio you need some real freak show geometry - typically heavily cambering a wing just like an airliner does with leading edges that move forward and down in conjunction with flaps at the trailing edge. You might even need to reflex the trailing edge at cruise. Molt Taylor's Mini Imp did that and he didn't create the idea.

I'm sure Patey will come up with something cool. I've got his video on right now.

As for electric
We're still a long ways from electric planes threatening the practicality of our dinosaur powered planes. BUT I grew up around r/c planes and remember when electric was a pipe dream. I was building and flying r/c in their early days and stuck with it until I actually preferred electric over nitro. I'm talking insane performance, clean, quiet and flew so long you got tired of watching them.

If I wanted to go to Valdez and make a showing I would find whoever is making the plane most of us know as the Kitfox Lite. Last time I looked them up they offered a titanium fuselage option. I would leave off everything not absolutely required for flight (covering only the wings and tail surfaces). And I would go electric.

While the weight of the batteries to make cross country flight practical are elusive, for a competition plane that only needs to fly for a few minutes that power could easily be achieved with a total power package that would compete with a two stroke.