IGS,
The other place you should find English bdm fiches is at your local LDS centre. I live in a provincial city in Australia, and our LDS has extensive (though not complete) indexes. Yes, searching them is laborious and the earlier years are hard to read. But I have had good finds just by sticking at the task.
I've had one subscription to 1837online, but unless you are pretty sure about the year/years you are looking for, it gets quite expensive very quickly. I doubt that I'll be subscribing to them again. For me, it's back to the good ol' LDS!
Also, if you DO find someone and you want to have a look at the parish records, the LDS has filmed many of them and you can order them in for $Aus 5 a film - don't know what it would be in the US.
Happy hunting!
MarieC