NEC ECC: Suitable form of contract for provision of site labour

We are the Contractor under an ECC with our Client and are looking to place a subcontract for provision of labour to support site installation work under an Option E / reimbursable basis.
The scope of work is purely the supply of bodies on site to be utilised under the supervision and management of the Contractor.
The Contractor’s PM has made it clear he would like to avoid the use / implementation of the Schedules of Cost Components and just have an agreed set of rates in place.
Any advice on the most appropriate form of subcontract would be most welcome.

Engineering & Construction Short Subcontract with the works being something like "Supply of labour to >insert what you want them to do