Taildragger
Just to back up what Warriner (and everyone else) said: buy or build an RV and you'll never regret it!
Remember the 4 is really a 1+1 with no instrument panel in the back and limited baggage space. The 6 is a bit more sociable and has a decent sized space behind the seats for up to 100lbs of baggage.
Wannabe fighter pilots obviously require a 4 for maximum fighterness but the 6 can give cumulo enemy air vehicles a pretty hard time too...
I co-built/own/fly a 6 and it such a brilliant aircraft. Ours is blessed with a 200hp motor and CS prop giving the following: take off and landing at mauw is never more than 300m even in nil wind (best I've done is one up, 1/3 tanks and 20kts on the nose which was 75m!). Climb at mauw/75kts is 1750fpm, cruise low level at 25/25 is 163kts, stall clean 52kts, full flpa 47kts. Fuel burn at 25/25 a tad over 40lts/hr. Range, no reserves (38USG) about 500nm. Not bad for a homebuild!
Even 150hp and a FP prop in a 4 or 6 will see easy cruise speeds of 150kts.
I had about 300hrs on Cessnas and a few on tail draggers when I converted but it wasn't a problem. Gear is a bit springy but get the speed right and it's fine. I've been in and out of tarmac runways with 15kts across and we both cope okay.
RV-4s were replaced by the grown up version - the 8, and the 6 by the 7 (uses 8 wings and things for commanality of parts).
4s can be found for £40k or so, 6s normally £45+.
My oppo is an ex Harrier pilot and he comes back with a smile on his face everytime which says it all!
Oh, and it's Vans NOT Rans......