Ubiquiti has proven very good for me. Have a look at this comparison.
»ubnt.ca/index2.php?option=com_wr ··· temid=56
Keep in mind that the "low throughput" devices on that page are capable of ~50 Mbps of sustained throughput, and the "high throughput" about double that.
At 750', the low range products will do fine if you have line of sight.
So essentially, you need to pick the radio that will work for you, get a pair of them, and set up a bridge between your two locations.--