PA-28
I don't have a clue about Parc Aviation so can't help you there but as someone who has compeleted the CTC ATP scheme I may be able to comment on that.
If you are going to pay to complete the ATP scheme you should go the whole hog and go for selection. To get onto the scheme you must be younger than 34, have CPL/IR, Class 1 medical and at least 2 A Levels (check the education requirements but i'am sure it's 2 A Levels). The selection is testing but not too difficult the first part being fill in the long form and now obligatory half side essay questions. The second and third take place at CTC a few tests and group discussions and final interview.
The fourth and final part of selection comprises of the MCC and JOT part. I gather this is the bit you are most interested in; it's an excellent fun course which includes 5 days of CRM ground school. Then 5 x 4 hr MCC sims using 737-700 FBS at the moment this is completed using auto pilot BUT may change. The final week is the 16hr JOT part all flown on raw data using the skills you learnt in the first few weeks. You will be surprised at how far you've come during your final test as you shut down one of your engines! For my money it was an excellent great fun course that if you pass places you in a hold pool for future jet jobs. If you don't pass to CTC standard you still get sent the MCC and CRM certificates.
Well worth the money and the wait. Do however check out Parc before you jump in.
Rollerboy