I have simplified my commercial floats down to 5 patterns that cover absolutely everything wherever I go. Guru MW Diamonds (glass stems) for on the deck, Drennan Crystal Margins for obviously margins and farbank/islands etc, KC Carpa 1's (slim body/carbon stem) for fishing through the water, especially that close swim (top kit + 2 or 3 sections) , KC Carpa slappa's for my shallow fishing and Chianti's for any finesse work or when fishing maggot/caster.
Firstly - the Mick Wilkinson Guru Diamonds are a superb and great stable float. Nice long glass stem which really helps fishing on the deck and especially in deeper water. Follow #neilofthenene's advice on float size/depth of water etc and take the tow into consideration but normally I carry these in 0.2g to 0.6g. You may want to go heavier if it is deep where you fish. Steve Ringer originally designed these floats with Mick Wilkinson back in the day to fish meat on the deck.
The Drennan Crystal Margin floats are a great little float. They do have a spring eye but I have never had any problems with them at all and I've had some serious bagging sessions and huge carp on them. I just love how they work - nice and short with a thick visable tip which is important for the far bank or tight to an island. I carry these from 0.2g to 0.5g. Don't be afraid to go heavy in the margins or tight across. Better to read the bites and make sure you are striking into proper bites and the thick bristle on this float helps loads with that.
KC Carpa 1's - perfect body shape (long and slim elongated rugby ball shape and decent thick bristle). I like these slim floats for helping me to read bites. The carbon stem allows you to do this perfectly and the thicker bristle allows for bigger baits like pellet, corn and meat. By simply laying the rig in and holding tight to the float, you can read the float and detect bites on the drop. Love using these on my close line and a great float for bagging! I carry these from 4 x 10 up to 4 x 16. Basically a big bait/bagging version of the Chianti!
For the majority of my shallow fishing, especially when you are slapping a pellet or piece of meat etc, the KC Carpa Slappa floats are hard to beat. Line through the float body just stops any tangles whatsoever and they will suspend any bait. Lovely thick wire stem helps them cock straight away. In my eyes they are the perfect shallow float. I really only use them in 0,2g and 0.3g. I also carry a few jigger floats for shallow fishing but that's a different topic in itself!
Finally, the Preston Chianti's. I have used these floats for years! In my opinion, for winter commercial fishing, general silvers on commercials at any time of year and also when fishing maggot/caster for whatever species these floats are amazing. Lovely slim body, carbon stem (again to help with fishing on the drop) and a sensible and visable bristle make these amazing little floats. I carry these from 4 x 10 up to 4 x 18.
Just a mention on float stems - I never normally use wire on a commercial. I know some guys do but this is mainly in winter. Wire is great for stability but can bend out of shape and is generally not suited to bagging. Glass stems are the best of both worlds when it comes to durability and stability.
Obviously the floats I have mentioned above are my personal choice which I have confidence in. There are many floats of the same sort of shape on the market by several manufacturers and it will be up to you to use some and see what you prefer. Just stick to the general rules regarding body shape and stems as I have mentioned above. Enjoy!!