Leon,
I completely agree with Genghis. The PFA is the way to go if you want to keep flying affordable and not get involved in unnecessary regulation and cost. If you have to have a CofA aircraft, however, a syndicate is the way to go. One way of setting one up that has been suggested to me is to just buy the airplane and bring it to your home field, then advertise for members (if you don't already have interested people onboard). That's much easier than getting a group of people and then going shopping for an airplane.
Also, consider other airfields than Elstree and White Waltham if you can. White Waltham charges extortionate prices in my view. For instance, if one is able and willing to drive down the M3 for a half hour, Popham charges £65/month for an outdoor tiedown and £175/month for space in a brilliant hangar (but availability is a problem at the moment). White Waltham charges £250/month for a dirty space in a clapped out WW2 surplus tool shed.
Another option to consider if you don't want to lose control of the aircraft but just want to defray costs is to buy the airplane and set up an arrangement where syndicate members can fly it but don't have to pay for a capital share. That way it's still your airplane to do with as you please. For instance, I've been in two groups like that. Didn't have to buy a share but put up a £1,000 deposit, paid an equitable share of the monthlies and a very reasonable rate per wet hour. Everyone won in that situation.
Good luck, in any case. You might also look for openings in existing syndicates. Hang around, drink coffee, talk to people, make some friends, let them know you're interested in buying in and someone may come knocking on your door. It happens.
Cheers,
Pitts2112