For health insurance options you can go through eHealthinsurance or a similar site, get a plan directly through Healthcare.gov or continue on your existing plan through COBRA.
Since you're ending your current employment, you'll also be eligible for the "Special Enrollment Period" which permits you to enroll in any plan offered directly on the exchange. Depending on your household income this would also qualify you for subsidies that would lower your costs dramatically. For this you must enroll through Healthcare.gov. The cap for subsidies on a family of 4 this year is around 95,400, below which you're likely to see some sort of tax credit. (Note: If your annual income after you leave your job is low enough, your family might actually be pushed into Medicaid instead of the subsidies which is also a viable option for coverage)
In terms of being ACA compliant all the major medical products you get through eHealth will now be complaint with the law. The plans will be practically the same as those on the exchange in many cases though you might have a few additional insurers that sell off exchange. Most of the insurance companies you see on the Pennsylvania exchange will have the same plans on and off. Going through eHealth will be more expensive however if you should be getting tax credits.
As some other posters have mentioned you'll also be offered COBRA to extend your existing benefits. The major drawback is this tends to be very expensive, especially if your employer was previously pitching in. One thing that is really important to note is that if you elect to use COBRA and not go through Healthcare.gov and decide to quit paying for COBRA later on, you will NOT be eligible for a special enrollment period. You will have to wait until the next Open Enrollment during this winter to choose an exchange plan.
From a cost perspective I would suggest looking at a plan through Healthcare.gov and see if you're eligible for any tax credits.