Proposal work in the Architecture, Construction, & Engineering field
I do a good bit of this work, engineering side
in my opinion it would be difficult for a non-engineer (or architect) to offer much to the package preparation (other than mechanics)
although for a large project many folks are involved (clerical, cadd, a/v, etc.)
but the 'meat' is developed by the guys that will actually have to execute the work
the selling point usually involves detailing a better way to do a technical project than the other guy, so by nature, very technical and project specific, not saying it is rocket science, but to sell design services for a wastewater treatment plant for example, you need to have a great deal of experience with them...that is why in most firms one of the sr. partners is usually the BD (or practice development) guy (and one is the operations/tech guy and one manages the business), but the proposal willl be a collaborative effort between the 3, ie, solution-method/resouces/execution/scheduling from the op guy, mark-up, cost, etc., from the business guy...the BD guy shakes the trees, does the smoozing, and puts the packages together and gets the agreement signed...
larger firms probably are a better bet for you, they likely have large BD depts.
in most states, to actually sell, or make the offer/pitch for these types of services, you have to be licensed
it may be done by proxy, but the deal must be signed by the licensed individual, and he must be in responsible charge of the process, from sale to design to commissioning
(a) In order to safeguard life, health or property and to promote the general welfare, it is unlawful for any person to practice or to offer to practice engineering in this Commonwealth, unless he is licensed and registered under the laws of this Commonwealth as a professional engineer.
some interpret this as meaning the offer (pitch) must be made by the engineer (or at least with him present and having it prepared under his 'responsible charge' or direct supervison and control)
Now to scope out companies to research.