I thank you all for your replies and advice. To Plumonpies, the reasoning behind wanting the Seneca is that if you do all the training on it surely you will be type rated at the end of it, thus cheaper for you or an air taxi firm to take on.
I wish to tighten the criteria further and do the training at a CAA test centre field, thus no positioning flights. Therefore on what we have so far it leaves Flight Plus, Bristol and Tayflite. I am grateful for your comments.