Several recent models offer all of those features, though the speed cams are, I believe, an extra cost option after a trial period.
What you do not mention is whether you need traffic information in the areas in which you drive. That will impact routing, and even the 'alternate route options' that you mention.
Another thing that impacts the final buying decision is the screen size that you will find helpful given your vision and preferences.
All of the following offer the features you requested: The GO 40/50/60 (4", 5" and 6" screens) and GO 510/610 units (5" and 6" screens, respectively), offer Live traffic using a small amount of data from your personal cell phone to achieve best routing. The more expensive GO 5100 and 6100 units have internal cellular modems to make their own connection to the TomTom traffic server. Each offers lifetime maps, and you may alter routing algorithms in advance, and at any time, request alternate routing vs. the currently planned route. The x10 and x100 units have capacitive screens and more convenient mounts. Moving down scale just a bit from those units, the GO x0 units use a resistive screen instead of a capacitive screen, and have mounts that are less convenient, but cost less.
Speed limits are included for many roads, but not all of them. 'Minor' roads still sometimes do not have speed data embedded in the map information. All units can be set to give an audible alert when exceeding a known limit.
This UK TomTom site may help you understand the differences.