Brad,

You can get the car down low by putting the spring in front of the axle (the so-called "Suicide" axle) and raising the perch.

It's a matter of choice, of course, but haipins or split 'bones look the best to me on a bucket. 4-bars are just too, well, today.

Batwings are batwings - tube or beam. You just have to get the right size to fit over the axle boss. It's either 2" or 2-1/4"