Rob,
I am one of the more recent converts to cloth diapers in this group, but here is what I do.
I have used both flats and prefolds with pins. I decided that it was easier for me to use the prefolds, although they take longer to dry. I usually add a booster for day wear and always for night wear.
A 44 square flat works for me. I usually use a modified angel fold.
Re pins, there are many different opinions. I usually use 2 pins with a daytime cloth diaper and 4 pins at night to insure better coverage at the sides as I am a side sleeper. Re size of pins, I have both regular diaper pins and jumbo 3" pins. The regular size is easier to insert into the cloth but bends very easily. The 3" pins are stronger but more noticeably more difficult to insert.
I find that to support the weight of a soggy and sagging cloth diaper the pins alone are not enough.

In addition to the required plastic pants I wear a onesie with the cloth diaper, even at night. At night the onesie becomes my PJs.
--John