Questions about older Mazda V6 (Xedos, MX3,…)

Hello guys, the Mazda 323 of my girlfriends lasted 20 years and the engine (4 zyl row) ran still better around worlds than with the 2000 polo of a friend. I want to try Mazda after 94 golf, 92er 5er and 92er Volvo 940 now also. I want to create approx. EUR 3500 for a MX-3 or Xedos 6, these two models say optically the most. Is the V6 in MX 3, in Xedos 6 and in 626 the same in principle? With how much cylinder capacity is there? Are there besides leaking valve lid seal What about the Xedos 6 with wind noise? Do they hold themselves in limits? Similar to what? Less than in Golf III and Volvo 900 I hope. It’s not determined on a 124 Benz, but I don’t want to burn 15 liters and move 1.5 tons when driving quickly. First of all I’ve had enough of this. So – Input