This appears to be more of an HR topic, but I've been interested for vendor management / contract language concerns. From what I can find, I think at least two of the EO clauses are required for contracts exceeding $10k. The veteran language threshold appears to be $100k, but it might be easier to apply the $10k rule of thumb to all. There is a $50k threshold for establishing a formal Affirmative Action Program and completing the EEO-1 report (if more than 50 employees).
For now, we plan to ask future vendors to insert the DOL's sample combined language in any contract that clearly exceeds $10k. If/when vendors refuse, we will likely send a follow-up letter to document our good faith effort to comply with the requirements. Here's the DOL's sample language combining the three clauses (bold text is required):
This contractor and subcontractor shall abide by the requirements of 41 CFR 60-1.4(a), 60-300.5(a) and 60-741.5(a). These regulations prohibit discrimination against qualified individuals based on their status as protected veterans or individuals with disabilities, and prohibit discrimination against all individuals based on their race, color, religion, sex, sexual orientation, gender identity or national origin. Moreover, these regulations require that covered prime contractors and subcontractors take affirmative action to employ and advance in employment individuals without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability or veteran status.