I use a SunPac auto 321 flash unit on my Autocord, as it's small, powerful and not only does the show mount allow the rotation up and down of the unit, but the flash tube is also adjustable with 180° of travel, side to side.
It has a guide number of 60 marked on it, 25 asa to 400, computed to 40 to 160, and three power levels, including manual and a sliding index.
A small fixed sync cord and an AC port, for a power supply, which I do not currently have and a single, hot shoe contact point.
Generally, I'm buy/scrounge only Vivitar 283, 285 units, but SunPac is also a maker I like, especially for flash units like this.
If I found one at the right time/price, I'd like to have a second unit for a 45° copying capacity.
If I were making a recommendation, I'd most likely suggest this small unit for any TLR, the Minolta Autocord and Sawyer's mk IV, being my two shooters.