Out of the RVs, the RV 4 (and 3) are the ones with the highest 'coolness' factor and closest to cult status. They are therefore also the most difficult to find and, logically, quite expensive.
Although you as P1 may like the tandem seating, it's worth checking whether your typical passenger would feel the same about sitting in the back
You might want to check the RV 6 (as far as I understand - also approved for gentleman's aerobatics), the RV 7 (similar but no aeros) and the RV 9 (updated model of the 7). Again, as far as I know, they all come in an '-A' version, e.g. RV 7A, having a tricycle undercarriage instead of the traditional layout. They should be easier to get hold of, and should be more comfortable to fly - making them better tourers (at least the 7 and 9) without being too much of a step up.
(Of course, getting a tail wheel conversion is not a biggie, but unless you will use it off grass and short runways, there is little point. Handling a taildragger on a hard surface can be a pain and may end up limiting where you go...)
(RVs are not approved for IFR flights, you may need to get an EASA CofA for that if you want to do serious touring, but then they don't tend to drink Mogas...)
If you like the Katana, how about the DA 40? the Diesel version can be quite frugal.
B.