You could try HML Shaw.http://www.shawandco.co.uk/right-to-manage.html They are an RICS and ARMA firm and have been accredited by LKP who are a voluntary org who are a "victim founded and led"lobby group against bad practices in leasehold management
Frankly its not that hard if all four of you agree. The LEASE site provides a good template, the Companies house forms for incorporation are straightforward and the staff are very helpful in helping which to complete and how, and the articles are standard under the SI.
The one bit of advice you won't get is that RTM companies have expenses and liabilities which extend beyond that which are Recoverable under the lease and therefore consideration has to be oven to the RTM members funding those expenses such as legal costs , losses* and day to day expenses like accountancy annual returns company secretarial costs etc.
* its often stated that the liability of these companies are intentionally limited to guarantee, however that could mean if say you pursue a person for non payment and don't recover all your costs then you are insolvent, and ultimately leads to losing the RTM company, and no guarantee the landlord will resume that function. I would take the advice of a Chartered Accountant on formation and prescribing the extendtof liability for such issues. This assumes that varying your leases is impractical.
Based on the information posted, I offer my thoughts.Any action you then take is your liability. While commending individual effort, there is no substitute for a thorough review of documents and facts by paid for professional advisers. More ramblings atleaseholdpropertymanager.blogspot.com