If you have not opted for one of the deals as offered by some of the sites in conjuction with the ferries, then the choices are either Wightlink which run from Portsmouth to Fishborne, or Lymington to Yarmouth, both of which are a 30 to 40 minute crossing.
Red Funnel operate from Southampton to East Cowes and is an hour crossing.
Prices are pretty much the same, maybe a couple of pounds difference, but price also varies on what time of day you cross.
The very early or late afternoon are cheaper than the main part of the day.
Dogs on both operators crossings can either be left in the car, or taken on the top deck but not in the lounges, which is not too bad except for the number of steps up to the top deck, and also if the weather is good. If it is wet, then expect to get very wet!!
Caravans do NOT need the status aerial, or spike, removing, there is plenty of headroom without having to touch them.
Food and drink on the ferries is expensive !!