By far the aircraft closest to the SP500 is the SPA Panther. When it comes to the high performance for the $ low wing single seater, Dan’s Panther is by far the best turn key solution.
Much inspiration & motivation came from Mark Langford’s KR2S, his web site http://www.n56ml.com is a great resource for this kind of work.
Before the Panther Dan’s Cleanx was another great motivation
Fellow ERAU Alumni Morgan Hunters Personal Cruiser was started / completed in the mid 2000’s
BD17 shares a similar Canopy / turtle deck / spin breaker setup.
There is some RV8 / Van Grunsven DNA in the 500 as well