Bronica offered an accessory called the Speed Grip. It fits the SQ series, and provides for thumb wind in place of crank wind. It has a shutter release and a hot shoe (not TTL), and allows the camera to handle rather similarly to a 35mm camera. The sync cord on TTL flashes attaches to the SQ-Ai's body to give TTL metering. There is also a standard X-sync terminal on the body and of course the hot shoe on the Speed Grip.
Guide to SQ series, including history: www.tamron-usa.com/bronica/sq_guide.asp
Regarding portrait lenses: The PS 110mm/4.5 1:1 macro is wonderful, but IMO, expensive overkill for portraits.
The 1:1 macro is much more expensive than the older macro PS, a 110 f/4, which focuses to 1:4.
The 110 is only equivalent to about a 63mm in 135 format.
The 150/4 is about equivalent to an 85mm, and focuses to 1.5 meters. The 135/4 is equivalent to a 76mm and focuses to 1 meter, meaning it will allow tighter portraits without an extension tube than the 150. KEH has one in BGN for $139 right now. The 180/4.5 is equivalent to a 100mm and also focuses to 1 meter, but I haven't seen those much. The 200/4.5 is equivalent to a 110, but only focuses to 2.5 meters, pretty much necessitating an extension tube (or a diopter on the front).