A few thoughts:
1) Geared head - this is probably the best for what you are doing. Products don't move fast so you don't need fast tracking, what you need is firm support and easy positioning. Geared heads give you fine control in each of the 3 axis of movement. So you can move it around and make very fine adjustments (they also have a pressure release to make bigger movements as required)
The Manfrotto Junior Geared head should suffice for most users who are not using a medium format camera or super heavy setup.
2) Ballheads - these are great for tracking moving subjects and being fast to adjust. You can lock off all the pressure and just have the head supporting the weight of the setup or you can pan and tilt (good ones often have a panning plate so you can pan without releasing pressure on the ball itself).
For products ballheads will be faster to position initially but you might find them a pain to make fine adjustments in a single axis without affecting the others.
3) 3 way heads - your basic pan and tilt head. Much like the geared head, but without the fine control options. You've already got one so if its working for you - great no need to update - if its not working for you identify the weakness/issue and see which other heads will suit.
4) Pistol Grip heads - some people love them, others hate them. Personally I had an earlier pistolgrip from Manfrotto and it was well made and fast to adjust, but, in the end, it was a pain. IT didn't have a pressure lock-off feature so that was one downside (I believe newer ones mostly do) as you had to have one hand on the pistol grip all the time to remove pressure if you wanted to track a moving subject. Furthermore you can't make adjustments in one plane at a time (again a weakness they share with ballheads).
Personally if I were doing product I'd use my geared head without question, however honestly mostly any head would work for most general products. The geared would just be the best overall.
On the subject of plates my preference is Arca Swiss (produced by Arca Swiss and Kirk). These are expensive and bigger than many other plates, but they have a unique design for each camera body (different for with and without camera grips) and lens collar. This design accounts for a metal lip on the plate which bumps up to the edge of the camera/lens collar - this means that it cannot turn on the tripod screw thread. Many plates (eg manfrotto) only have a rubber surface to prevent rotation and, often as not, you have to screw them down very hard to avoid any rotational slippage (esp if you're using varied angles).
You will need adaptors for things like manfrotto heads (since they use different quick release plates and using a manfrotto quick release plate on the base of an arca swiss one defeats the point of using the arca swiss). The Geared head mentioned above (Junior geared by manfrotto) uses a unique quick release plate design (so the generic manfrotto adaptor for arca swiss won't work). There are adaptors for it out there, so do search for them if you go down that path.
Of course there are also tripod heads out there that have arca swiss mounts on them from the start so you can always get a geared head built with one attached (or any other head type). I don't own a geared head like that so I can't suggest a product name.