I approached ESOfund in the past, and did not ultimately use them, but not by any fault of theirs. They were very professional, helpful, and knowledgeable about my options and provided very good information about my available choices, even ones that wouldn't benefit them (I did extensive independent research on the decisions available and on their suggestions).

I believe their mission statement is to take the risk for you, which includes AMT if necessary, in exchange for some percentage of your stock to be negotiated. There's no risk in reaching out.

As far as AMT, I believe (off-hand) it's 18% of all income if it would be greater than your existing tax burden. So if you make $100,000 and are currently taxed 30%, your current tax is $30,000. If you exercise stock (where the gain is difference between your equity plan and the value as of the latest 409A, multiplied by the number of options exercised), that counts against AMT.

In this case, $18,000 would be your normal income against AMT, and you could gain another $12,000 in AMT without paying any more. This means gaining approximately $66,000 in value from the exercise without paying additional taxes. You would pay 18% on the rest of the value gain. For another $1,000,000, you'd pay on the order of $180,000.

Note: talk to someone who does this professionally, perhaps a tax attorney, as my word is from memory based on my research from a while ago.

If you believe in your company, or at least believe the stock will be liquid, I absolutely recommend finding a way to exercise your stock. All the better if you don't take a tax burden.

I also found out there's some kind of tax thing where you can preemptively exercise options (at grant time?) which won't be taxed as a gain because the value hasn't changed, then you just get the options as they vest (though it's a little late for that now :P)