Had a look at a Rans S10....
But doesn't meet criteria (2). Nor did the one I looked at meet criteria (6). However the 4 stroke Rotax is often fitted and its a fairly simple job to replace the engine I'm lead to believe. With the 4 stroke fitted, it should cruise at 90-100kts, with a good range.
Nice aircraft, a mini Extra 300, +9g / -6g ultimate, aerobatic with an inverted fuel system fitted, 2 seats, taildragger with excellent short field. Can be a bit of a handful though due to its inherrent instability.
Available for under £10,000.
EA