Many of these sources are reviewed here. This is a blog post which I will expand based on feedback from readers and additional research.
FedBizOpps: FBO from the General Services Administration is the best known source of federal business opportunities. Many of the paid services list below include FBO search results. Be sure to try the advanced search feature.
Deltek GovWin: Deltek's flagship service GovWin IQ is the largest and probably most comprehensive source, purchased by nearly every large government contractor. When GovWin was hacked in 2014, a news story claimed that 60,000 customers were affected, so this represents a large user base. Deltek has purchased a number of competitors over the years, such as FedSources, Centurion Research and Input. Deltek is one of the most expensive of these services. Some users find the CRM user interface a bit out of date. Integration with Salesforce is available.
Onvia: Onvia covers state and local government and grant sources as well as federal opportunities. From my experience, their state and local coverage is the most extensive of all these services. Onvia creates white papers, articles, webinars and analysis which are available without a subscription. I enjoy their quarterly state and local procurement snapshot such as this one on Q3-2015. In August 2016, Onvia added integration with Microsoft Dynamics CRM. They also offer integration with Salesforce.
Bloomberg Government: Bloomberg is the largest new player in many years, bringing the same quality and breadth of coverage for which they are known in the financial industry. Bloomberg hosts events with government and industry leaders as well as briefings from its analysts. I have attended Bloomberg events and the quality of their presentations and analysts is quite high.
Govini: Another relatively new player that, like Bloomberg, has recruited veterans from its competitors. According to this 2014 article from the Wall Street Journal, Govini has a plan to gather and publish contracts data from all over the world. It was described in the article as a startup with 40 people and about 200 subscribers.
FindRFP: Contains U.S. and Canada government solicitations. You pay based on the geographic segment you would like to search. You can try an anonymous keyword search to get a sense of how many search results you will get, although you will not be able to see the full opportunity detail without a subscription. Plans are $19.95/mo. for regional and $29.99/mo. for national with annual plans of $199.50 and $299.50 for regional and national respectively.
Bidspeed: Merges data from multiple sources including FBO and provides templates for responses as well as additional services.
BidSync: Free and paid plans available. Some government agencies publish bids through BidSync and user their infrastructure to manage amendments, proposals, and other documents. A few white papers are available. A review has been posted on Capterra in the category of procurement software.
GovSpend: GovSpend collects bid, purchase, contract, and contact data directly from U.S. local, state, and federal agencies. In August 2021, GovSpend acquired FedMine.US.
Several procurement sites seem to be similar in terms of their offering and their data. I had a harder time finding review information on the following:
GovernmentBids.com: Low cost subscriptions from $44 to $131/month.
GovDirections: Local, state and federal government bids. Offers daily update services called RFPDelivery. Federal data seems to be mainly from FBO.gov and FPDS.gov.
GovTribe: Showing government agencies, vendors, contracts, solicitations, projects and more. Standard monthly subscription is $250 for 2 to 10 users.
BidClerk: Specializing in bid opportunities for the construction industry.
BidPrime: Pricing is by region, from $400-1,100 per year.
AmericasBiz.net: Administered by the North America Procurement Council, Inc. PBC (NAPC), a Colorado public benefit corporation, it includes some commercial as well as government solicitations.
USAOpps: Inexpensive service with free trail available.
EZGovOpps: Inexpensive service with free trail available. Seems focused on federal with data sources listed here.
EPipeline: Pricing not shown on website. Listed as a subsidiary of Mediagrif Interactive Technologies Inc. in Bloomberg Financial.
SmartProcure: Started in 2008. Doesn't track bid opportunities. SmartSearch is $425/mo. and SmartExport is $675/mo. billed annually.
I will add more information and links to each to these. So far I have found none of these providers offering integration with Dynamics 365 but some offer integration with Salesforce.