Soliciting recommendations for DB admin

[Guest Spock]

An employer with 8000+ lives wants to expand the list of potential recipients for its DB RFP that will include actuarial, admin, investment consulting, legal&compliance, domestic and international plans. Aside from the "big name players" can anyone recommend a boutique-type firm that might be able to provide services to support a DB plan that is complicated due to an extensive legacy plan/grandfathered benefit scenario? Client is located in the NYC metro area.