Comanches come in many flavours; as already mentioned (assuming we are talking singles) you can have from 180 to 400hp. The 400s are very rare and expensive but the 250/260s are not. There is a large and very active owner community worldwide with plenty of help/advice and camaraderie available if you want it.
Fuel capacity varies from 60usg to 120usg with up to six tanks, including aftermarket tips available. Adding tip tanks gives a MTOW increase that takes care of the extra 30usg fuel.
I have a 1960 PA24-250 with original carb feed and it will easily take four, normal sized, adults with full (60usg) fuel and some baggage. Legroom in the back is more than generous.
I tend to cruise at 150mph for around 13usg/hr but I baby it - faster and leaner is possible.
Costs are similar to an Arrow but IMHO it is a far prettier aircraft. They are smooth and harmonious to fly; if you are stepping up from a trainer you will notice a big difference. Comanches have much more in common with Mooneys than their Cherokee descendants because, so I've heard, Bill Piper bought the design from Al Mooney.
These days you won't find anybody using them for training so they are mostly privately-owned and well looked after.
And Jabberwock - have you seen the Ravin 500? A South African pilot thought like you and has a composite Comanche copy (with up-to-date improvements) for sale. They are marketing them in the USA now but I don't suppose they can be kept in Europe. Shame.