In 2wd I have only run a Vega RB5 so am not in a position to compare cars but can add my two cents in support of the car. It is expensive as you need a donor car and a conversion, but then so do several on your short list...
Since I have had it I haven't broken anything, not a single thing in 4 months which is remarkable really. I'm no F1 driver, I'm average at best and I have had some almighty smashes including somersaulting it about 8 times at the end of the straight and it got put back on track in A1 condition. I raced a B44.1 for a similar length of time and went through 3 wishbones, 2 shock shafts and had dozens of ball cups pop off mid race, I've not even had a single ball cup come off the Vega, it is solid as a rock. If you drove it into a wall it would probably knock the wall down!
Also, I notice you say that Stotfold would be one of your likely local tracks... This is my 'local' as well and Kev Lee often races there so help of the highest order is often on hand to help with set ups and advice.
As for what cars are popular at Stotfold, there isn't a dominant brand really. There are plenty of X6, 22's, Vega's, Cougars, 210's. The only cars I would say are weaker represented at the club meets week in week out would be the B4.1/C4.1 and the Ansmann cars. There are some there, but not as many and not as often.